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National Park Service Will Cite AWD Drivers for Driving on 4WD-Only Trails

131 points by rntn 2y ago

COGlory 2y ago
While there are rare situations where locking differentials are meaningful, having been in many hair raising off-road situations, including a real life or death one, I'd much rather have AWD and clearance, than 4WD and no clearance. That is to say, I'm not convinced by the article's hypothesis about locking diffs. It's extremely rare to need to deploy those: beached, or slow starts up vertical surfaces like boulders. An AWD vehicle with good tires and good clearance is really quite good. Bonus points if you don't care about wrecking it.
- NDizzle 2y ago
  What 4wd vehicle doesn’t have good ground clearance?!
  - tom_ 2y ago
    First generation Subaru Justy.
  - jofer 2y ago
    Most stock pickups, actually. You'd be surprised how low the clearance is on a stock f150 without the various off-road packages. I.e. you can easily have a pickup with basic 4wd but only 8 inches of ground clearance. That's technically "high clearance", but not by much, and the poor approach, departure, and break over angles make it tough too.
  - ezfe 2y ago
    Subaru Impreza has less than 8 inches of ground clearance, which is the threshold they use in the link.
    - garciansmith 2y ago
      Imprezas are AWD, not 4WD, like all Subarus (well, the BRZ is RWD). The whole point of the article is that there's a difference!
  - ghaff 2y ago
    Depending on your definition of "good," probably most of them. While I have been guilty of taking questionable AWD rentals on questionable roads in places like Death Valley when younger, you really want properly-equipped Jeep Rubicons and the like that you're not going to get from the average car rental place.
  - COGlory 2y ago
    None, which is my point. I'm trying to say I suspect it's ground clearance, not locking differentials that matters on these roads.
    - relaxing 2y ago
      It is both.
  - kube-system 2y ago
    Suzuki X-90 ?
- lamp_book 2y ago
  > 4WD and no clearance I think I've only really seen this as a Honda Element - otherwise I'm not sure it meaningfully exists. The reality with most AWD cars is that their important guts are hanging lower compared to 4WD trucks even when the paper ground clearance is similar. My previous car was AWD and I have a 4WD SUV now largely for off road performance, and there's no question 4WD (particularly 4LO) is much better at getting unstuck in trail conditions. The AWD is definitely superior for icy pavement in the cold months though. > Bonus points if you don't care about wrecking it This was actually what mainly pushed me over to the 4WD side instead of something like the Forester. The crossovers can actually get you to a lot of places but they do get thrashed if you do it enough. They are still more geared for pavement use but, if you're wrecking your suspension off road, the on road performance isn't gonna be great either.
  - ADSSDA 2y ago
    > I think I've only really seen this as a Honda Element What Honda element had 4wd? As far as I'm aware they were all (a pretty bad) AWD system.
    - lamp_book 2y ago
      They marketed it as 4WD anyway.
  - soganess 2y ago
    I'm working from memory here, but I believe early 90s Audi "quattro"s (like the 100) had the feature. That said, I think we are very much in "the exception that proves the rule" territory.
  - toast0 2y ago
    > I think I've only really seen this as a Honda Element - otherwise I'm not sure it meaningfully exists. Maybe it's not meaningful, but vans in the 80s and 90s were often offered with optional 4x4, sometimes with a locking differential. An unmodified Astro or Aerostar doesn't have a whole lot of ground clearance, but could fit the definition of 4wd if properly optioned and probably wouldn't be suitable for these trails unless it gets some aftermarket help. Of course, few of these are running anymore. 4x4 kei vans can get pretty serious too, but not a lot running on US national park fire roads.
- Zandikar 2y ago
  > That is to say, I'm not convinced by the article's hypothesis about locking diffs. I'm not an offroader, but I did own a vehicle without a locking diff, that I later upgraded to having a locking diff (slapped a G80 on the rear of an 80's GMC Sierra) and that made a huge difference even on pavement in inclement weather. Granted, that was a RWD pickup with very little weight (typically) over the drive wheels. I'd honestly be shocked if the impact was minimal in truly offroad conditions. Granted, that's RWD which is even less than AWD or 4WD, so by no means apples to apples comparison there, just my 2 cents. That said, this isn't a binary thing (locking vs open). There's a wide variety of AWD technology out there, and I could nerd out on the specifics, but at the end of the day, some are very limited in their ability to send power to one set of wheels vs the other, and may not have locking/limited slip diffs at all, and just use brakes to prevent wheel spin. I will say, Subaru (especially the higher/sportier trims like WRX/STi) can often hang and even shame some 4WD vehicles in some conditions. There's no shortage of videos of Subarus helping a 4WD out of a jam, or completing a course they could not, but how much of that is a function of their specific AWD tech and limited slip diffs vs proper tires and lighter weight and any number of things is a matter of debate that I'm not qualified to weigh in on. Again, am a gearhead, but not an offroader. So I suspect it's not so much the Park saying "Subaru/AWD can't cut it" but rather, keeping track of which years, brands, models, trims, and/or potential optional equipment does cut it is a much more massive headache to keep track of and verify than just saying "4WD yes, everything else no", and I can't really fault them for that.
  - pandaman 2y ago
    I am not an off-roader by any stretch of imagination, but I figure the AWD works like single axle drive with a simple diff on each axle i.e. if one wheel has no traction then all torque goes to that wheel and zero goes to the opposite one. I once got stuck on pretty solid pavement in a RWD car when one rear wheel hanged off a curb and lost traction, after that the car could not move as the only wheel getting torque was the one hanging off the ground. I figure the other axle would still get torque on an AWD as they usually have some kind of limited slip mid diff effect from whatever scheme they use to distribute torque between axles, but if you hanged out a wheel on each axle then an AWD vehicle would become stuck too?
davidbanham 2y ago
Locking differentials are very useful in particularly challenging terrain. Think step rough rock climbs or soft sand. For punting along an average fire trail or dirt road, though, it’s clearance, strong tyres and suspension travel that’s more important. A Subaru has none of the above. They make great cars, but they’re not an off road vehicle.
- quasse 2y ago
  I say this as a Jeep owner; it's ridiculous to claim that Subarus are not appropriate for punting along fire trails. The average obstacle on fire trails in the PNW is mud or large potholes, both of which a Subaru is perfectly appropriate for. A Crosstrek has 8.7in of ground clearance which is plenty compared to say, a Prius. That being said, the trail from the linked article is not an average fire road. They have genuine rock hazards, steep slick rock climbs and descents, and deep sand. I'm sure the national park service is extremely tired of people getting stuck and setting off their emergency beacons because they drove inappropriate vehicles into the park.
  - barkingcat 2y ago
    the previous poster didn't say that subarus are not appropriate for fire trails, it's saying that Subaru's are not off road vehicles for "particularly challenging terrain", as in "Think step rough rock climbs or soft sand." What it does say is that for fire trails, "clearance, strong tyres and suspension travel" are more important, which the Subaru does quality for.
    - quasse 2y ago
      > it's clearance, strong tyres and suspension travel that’s more important. > A Subaru has none of the above. Maybe you and I take different meanings from the phrase "none of the above". My intended meaning was that a Subaru has "some of the above".
      - davidbanham 2y ago
chubs 2y ago
I have a new Tiguan. It’s supposed to be AWD. In reality though, even when in off-road mode, it’s basically front-wheel-drive as evidenced by the fronts spinning when you accelerate hard into a gap in traffic. Most cars that use a Haldex oem for their awd act similarly.
- OrigamiPastrami 2y ago
  The neat thing about the Haldex is that with just a software tune you can substantially improve the performance of it. The hardware is actually far more capable than you'd ever know with the enormous amount of slack that's programmed into it from the manufacturers. Obviously this voids your warranty, but it's a fairly low-risk modification.
  - chubs 2y ago
    Ok I’m interested… how is this doable?
    - OrigamiPastrami 2y ago
      I only spent a few minutes on Google so you'd have to do your own research since I am not familiar with the Tiguan although I know the MQB platform it's built on. Anyway for the Tiguan you might have to actually order a part, there might not be enough interest in that model specifically. If you google "tiguan haldex tune" it will take you in the right direction. This tune is somewhat common for the performance cars on the MQB platform, like the Golf R and RS3. I can't think of any reason it would cause trouble for the Tiguan but it's mostly track junkies doing these modifications, not offroad enthusiasts.
- SkyPuncher 2y ago
  Do you have adjustable drive modes? When I put my car into sport mode, it does nearly 50/50 power application. When it’s in normal or eco, it will put 80% of the load on the front tires, then only increase rear tire load as needed.
williamstein 2y ago
"Up to six months imprisonment" for repeat offenders.
- deleted 2y ago
  [deleted]
- nofunsir 2y ago
  Whatever happened to cruel and unusual?
drewg123 2y ago
I wonder what this even means in the context of EVs? Eg, some vehicles have a motor per wheel...
- op00to 2y ago
  The actual letter says “High clearance 4WD”. There’s more to off-roading than traction.
  - leoh 2y ago
    No, off-roading is about having the right equipment that doesn’t cause other people problems or problems that you regret. If I’m on a well-graded gravel road, it should be fine to take a Ferrari on it without stupid rules getting in the way.
    - deleted 2y ago
      [deleted]
    - seattle_spring 2y ago
      These rules are not applied to "well-graded gravel roads." There are specific routes that require the specific equipment, and none of the requirements are unreasonable given the demands of the terrain.
  - dag11 2y ago
    What is considered "high"? The Rivian R1T's clearance goes up to 14.9 inches, and has a motor per wheel. Does it count?
    - op00to 2y ago
      Probably? I think greater than 9” is considered high clearance, but the actual required clearance likely depends on the particular trail.
- mikestew 2y ago
  "Some", which is what, just Rivian? I wouldn't take our dual-motor Hyundai Ioniq 5 down anything more technical than a forest road, if only because of its (IIRC) 7 inches of ground clearance. And I imagine the AWD software is tuned to icy suburban streets, not something like this trail. Best I can tell, the AWD is supposed to get you to the ski slopes, not down the Rubicon.
ADSSDA 2y ago
As pretty much anyone who offroads knows, AWD vehicles absolutely tear up the trails vs a proper 4wd with lockers, since AWD relies on detecting tirespin (ie, destroying trail) to determine when it needs to activate.
- londons_explore 2y ago
  It's really just poor sensors and software. AWD can theoretically work far better than a 4WD with diff locks, because it can simulate, based on the steering wheel angle, the exact speed each wheel should turn, and 'lock' each wheel to that speed giving zero slippage. Just a shame that the sensor -> computer -> actuator feedback loop seems to be 200 milliseconds or more, so AWD vehicles just end up having different wheels slip semi-at-random till that wheel gets the brakes activated 200ms later.
  - jofer 2y ago
    AWD has come a long way in that regard in the last few years. It's still highly variable from manufacturer to manufacturer, but systems that use internal clutches alongside brakes (and not only brakes) to control wheel movement + tight feedback loops can really do a great job of minimizing wheel spin. They get a lot of hate, but the bronco sport has the best AWD system I've driven to date in that regard. And with that said, it is still the type of thing the Park Service would rightfully cite as not a proper 4wd. 9ish inches of clearance is not much, and the lack of a low range will bite you. I've taken mine on plenty of milder 4wd only trails in parks (e.g. black gap in big bend plus tons and tons of forest service roads), but I'm certainly not going to do elephant hill in canyonlands with it. That's what the dedicated off-road rig is for. There are "4wd only" trails in national parks that high clearance AWD is fine on. The rangers will tell you which ones those are. Canyonlands is a different beast than most national parks. Canyonlands has some very gnarly trails open if you have a permit. Lookup dollhouse sometime. Beautiful, but insanely technical. Elephant hill is better known and a bit milder.
    - sciurus 2y ago
      > I'm certainly not going to do elephant hill in canyonlands with it Someone has, albeit with a slight lift. https://www.broncosportforum.com/forum/threads/off-roading-on-elephant-hill-trail-in-canyonlands-ut-trip-report-mods-that-mattered-most.7448/ https://www.broncosportforum.com/forum/threads/off-roading-o... From their report of "the little three-, two- and (very occasionally) one-wheel-yeet maneuver", it sounds like the lack of suspension travel was the main issue. The details of your AWD or 4WD system don't matter as much if you can keep your wheels on the ground. Still, just because they were fine doesn't mean someone else would have been. The main risk seems like doing a somewhat technical, off-the-beaten-path trail alone regardless of your vehicle's capabilities.
deleted 2y ago
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olliej 2y ago
I still dont understand the difference between 4wd and awd, but the article spends more or less the entire time talking about locking and limited slip differentials and how AWD generally don’t have them which is “why they’re not allowed”, while also acknowledging that just being 4wd doesn’t mean there’s any kind of diff lock either. If the actual reason ia the difference in how the diff is locked, then access should be restricted on the basis of that, not on the mechanism the wheels are driven. I assume that the actual reason for the 4wd only rule is because there is a real difference in how they work?
- barkingcat 2y ago
  This article says a bit about the differences: https://www.caranddriver.com/features/a27630736/awd-vs-4wd/ https://www.caranddriver.com/features/a27630736/awd-vs-4wd/ The primary reason there's a 4WD vs AWD distinction is the ability to lock the differentials, and that determines the mechanisms that the wheels are driven by. And that's why they use those terms in a prescriptive law context. to simplify: AWD -> power gets to all wheels (driven wheels) but wheels are usually allowed to spin at different speeds to facilitate pavement driving and turning. 4WD -> power gets to all wheels, but there is a locking mechanism that locks all wheels so they all turn at the same speed - if you know the physics of turning objects, it means turning while underway is either impossible or damaging to the drivetrain. This is however, useful in mud or rock, or challenging terrain. When on mud or rock or whatnot, you turn, move a bit, stop, check, turn a bit, move, stop, check, turn a bit, movie, stop, etc. So the fact that all wheels turn at the same time is an advantage. The reason some 4WD don't have a "differential lock" is that it's fused by bare metal - it doesn't need a lock because it's welded together, so no lock needed! The car and driver article gives an easy test: if the car manual tells you "this is bad for road driving" - that's 4WD. you might think "well 4WD is terribly useless for regular driving" and you would be entirely correct. That's why most 4WD cars incorporate both modes of driving mechanisms so they can switch. You can tell apart a permanent 4WD / full time rock climber by the owner needing to use a trailer to move the vehicle instead of driving it over the highway, usually they use a pickup truck or SUV with a regular drivetrain to haul gear and pull the trailer with the 4WD vehicle to the trailhead, unload, then go into places like Death Valley Back Country or Moab with the 4WD vehicle.
i_am_jl 2y ago
Not sure about this park, but elsewhere the NPS has made this distinction clear. Death Valley's map makes clear that a high clearance crossover, high clearance 2WD or high clearance AWD vehicle is one class, and 4WD vehicles are another. See page 2: https://www.nps.gov/deva/planyourvisit/upload/508-Backcountry-and-Wilderness-Access-map_.pdf https://www.nps.gov/deva/planyourvisit/upload/508-Backcountr... EDIT: https://www.nps.gov/cany/planyourvisit/maps.htm https://www.nps.gov/cany/planyourvisit/maps.htm has a whole lot of maps for the Canyonlands and none of them make this distinction, maybe this isn't as apparent at that park.
- SkyPuncher 2y ago
  It was very clearly defined, but finding the definition would require you to go looking for it.
- rocqua 2y ago
  Notably, this marks a 4WD as having a low gearing case, ot says nothing about locked differentials.
- ghaff 2y ago
  The Death Valley one seems reasonable--if a bit conservative, which is appropriate. And high clearance seems an appropriate distinction--which the rangers will make as well. It's probably also worth noting that for places like the Racetrack having appropriate tires (and full-size spares) is important as well. I wouldn't have an issue driving there on my own but I wouldn't probably do it in a random rental.
leoh 2y ago
[flagged]
ryandrake 2y ago
It's good that amongst the know-it-all Reddit responses typical to these kinds of education threads, the OP learned something about his or her car, and came out of the thread with a better knowledge of the differences between 4WD and AWD. One of the Redditors summed up the stupidity of these marketing terms: All Wheel Drive? Cool. There are four wheels. All of them means four. I'm sure many people's knowledge of their car ends there. The terms 4WD and AWD are as misleading as USB Full Speed vs. USB High Speed (quick, tell me which one is faster without looking it up?)
- xyst 2y ago
  [flagged]
- deleted 2y ago
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- jrs235 2y ago
  AWD means that all the wheels receive power from the power train. Most AWD will stop providing power to a wheel if it loses traction (spins). This is because they have an unlocked differential. 4WD typically means all four wheels can receive power from the power train and can be locked so that that will not lose power if they spin.
  - falcolas 2y ago
    > AWD means that all the wheels receive power from the power train. I used to think that, until my car (Dodge Charger) with AWD had its tail swing out on ice. Basically, AWD for that vehicle meant "Rear Wheel Drive until it slips," at which point the front wheels would receive power. Same with my Toyota Prius, though it was FWD until it slipped, then the rear wheels kicked in. Even my AWD EV with dedicated motors doesn't have them all active all the time. The Subaru is the only AWD vehicle I've owned which was full time 4 wheel drive.
    - Klonoar 2y ago
      We typically refer to these as RWD-biased AWD, etc. BMW’s xDrive is a RWD biased AWD.
adrr 2y ago
Whats the difference between AWD and 4WD? Luxury SUVS are AWD and have transfer cases with locking diffs. G Wagons, Range rovers, Cayennes. The luxury crossovers have limited slip diffs and brake torque vectoring. Edit: Not sure why i am getting downvoted. Here are the specs to a G Wagon. AWD with front and rear diff locks. https://www.caranddriver.com/mercedes-benz/g-class/specs https://www.caranddriver.com/mercedes-benz/g-class/specs
- SkyPuncher 2y ago
  G wagon is a proper 4WD vehicle. It might be able to drive in AWD modes, but it has proper diffs to do it. There are loads of exceptions, but generally AWD vehicles have weaker or non-existent locking diffs. For example, I believe my AWD vehicle simulates locking diffs with clutch plates. Those clutches can and do slip. They’re effective at keeping the wheels “mostly locked” but not true 4WD. Further, most of the brake based torque vectoring required “slip detection” that’s only possible when a wheel spins. These systems aren’t really perfect in actually locking out motion on a free wheel. They kind of have to let them slip from time to time to check condition. These systems also tend to allow a lot of spin before they kick in - that years up roads.
avar 2y ago
With reference to previous absurd but technically correct interpretations of US national park rules[1] I'd like to suggest a way to comply with the rule in question [2], which states: High clearance four-wheel drive is required on motor vehicles travelling on [...] Take a 2WD vehicle, then bolt an extra set of wheels onto the drive axle (the tires are apparently optional). The vehicle would still need to be high-clearance. Or, if you're feeling really adventurous, just glue a set of LEGO wheels to the center of the hub. Those wheels would demonstrably have a high clearance, and comply with the rule as written. 1. https://news.ycombinator.com/item?id=36453856 https://news.ycombinator.com/item?id=36453856 2. https://www.nps.gov/cany/learn/management/compendium.htm https://www.nps.gov/cany/learn/management/compendium.htm
- metaphor 2y ago
  Play stupid games, win stupid prizes. > Definitions: > High Clearance Four-Wheel-Drive (4WD) Vehicles > A Jeep, sport utility vehicle (SUV), or truck type with at least 15-inch tire rims and at least eight inches of clearance from the lowest point of the frame, body, suspension, or differential to the ground. Four wheel drive vehicles have a driveshaft that can directly power each wheel at the same time and a transfer case that can shift between powering two wheel or four wheels in low or high gear. All wheel drive (AWD) vehicles do not meet this definition.
  - avar 2y ago
    Just in case it's unclear, I'm not being serious here. Still, it seems to me that the wording still allows for some rules lawyering. When they say "directly power each wheel" they clearly mean the four wheels attached to the OEM axles. But I think their wording is open to arguing that it's any four "wheels" of your choosing, and now that your drive axle has two wheels on each side... The rest of the wording allows you to flip between arguing on the basis of your now-four wheel drive axle and the stock axle. After all, they're not saying "those two wheel or four wheels". Different sets of four wheels on your now six wheel car should satisfy all the criteria. However, the mention of a transfer case is a showstopper. I shouldn't have mentioned 2WD. But given the above contortions e.g. a BMW X5 with 216mm (8.7 inches) of clearance should qualify. The manufacturer obstinately insists that it's not an AWD, but "xDrive". The gear ratio of the AT even is so low that you can idle at a standstill while in gear!
olalonde 2y ago
Stupid question but why does the National Park Service care? I can't imagine people just abandon their cars when they get stuck?
- 3np 2y ago
  "I'll get it after the weekend" Also, rentals.
- kccqzy 2y ago
  Creating less work for park rangers. If people drive unsuitable vehicles and get stuck, they will call emergency. That's independent of whether they abandon their cars.
- akerl_ 2y ago
  No, they don't abandon them: they call for help and require both government and commercial assistance to get their cars unstuck.
- davidbanham 2y ago
  Recovering a car from a remote area can be a big job. Not only do you need a vehicle capable of getting into and out of the spot where the first car got stuck, it might need to do so while also carrying the first car. Dragging the first car to where you can get it on to the recovery vehicle can cause significant damage to the trail. Repairing that can be a big job when you can't just drive a tip truck full of sand/gravel/rocks to the spot. It's not at all outlandish for the consequences of a stuck Subaru to pretty quickly run to "We need to contract a high lift capacity helicopter for a few days to fly in a half tonne of gravel and a repair crew". And then there's the fact that to some degree, you're endangering the people who need to come get you.
  - acdha 2y ago
    > And then there's the fact that to some degree, you're endangering the people who need to come get you. This is especially true because the same kind of people who will drive somewhere out of their league are more likely to also be doing so in bad conditions with inadequate preparation so the rescue team might be rushing at night, in adverse weather, etc. A couple of people I knew who went hiking or mountain biking in the BLM land east of San Diego had stories about sharing food and water with people who’d only packed driving treats and forgot that SUVs can get stuck pretty easily no matter what the ads showed.
jasomill 2y ago
The cited regulation[1] defines a "high clearance four-wheel-drive vehicle" as A Jeep, sport utility vehicle (SUV), or truck type with at least 15-inch tire rims and at least eight inches of clearance from the lowest point of the frame, body, suspension, or differential to the ground. Four wheel drive vehicles have a driveshaft that can directly power each wheel at the same time and a transfer case that can shift between powering two wheel or four wheels in low or high gear. All wheel drive (AWD) vehicles do not meet this definition. First, note that all recent Crosstrek models have 17" wheels and minimum ground clearance of 8.7" or more, so the only potential issue is "all wheel drive". The last sentence is at best non-normative, so the actual requirements appear to be: 1. The ability to power all four wheels at once. 2. A drivetrain that includes a transfer case capable of switching between two- and four-wheel drive and, in four-wheel-drive mode, between two distinct gear ratios. In particular, the regulation says nothing about differential locks. Obviously the Crosstrek has (1), but not (2), so the citation is valid. OTOH, (2) not only excludes Subaru-style all-wheel-drive systems and AFAIK all electric vehicles, but also several full-time four-wheel drive vehicles clearly designed for off-road use, including the Toyota Land Cruiser[2] and the military-issue AM General HMMVW[3], for no other reason than the lack of a two-wheel drive mode. [1] https://www.nps.gov/cany/learn/management/compendium.htm https://www.nps.gov/cany/learn/management/compendium.htm [2] https://www.landcruiserforum.com/manuals/2024-toyota-landcruiser/OM24J1QRG.pdf#page=43 https://www.landcruiserforum.com/manuals/2024-toyota-landcru... [3] https://gear-report.com/wp-content/uploads/2017/03/Operators%20manual%20for%20the%20M998%20series%20truck.%20June%201991_TM-9-2320-280-10.pdf#page=47 https://gear-report.com/wp-content/uploads/2017/03/Operators...
- davidbanham 2y ago
  Definitions are hard. By that wording, any Land Cruiser outside the 70 series is forbidden because they're a full time 4WD. Nobody will argue that an 80, 100 or 200 series cruiser isn't a very capable 4WD. I don't begrudge the parks people that wrote the regulation, though. Fundamentally what they're trying to say is just "Don't be dumb, only drive the trails in a vehicle that you know is capable, and if you don't have the experience to know that you have your answer". The job of the regulation is to give them the ability to deliver an enforcement action where it's warranted. The job of the rangers is to use their judgement in a given situation, and either pull someone up or just wave hello. That's what's happened here, the system works.
thrill 2y ago
4WD is poorly defined, and the NPS shouldn't be using it, especially by trying to classify an AWD system as something of lesser capability. The SAE even recommends using the term AWD along with 8 different subclasses, none of which use the term 4WD. Jalopnik can hand-wave all they want about what the NPS "means" but the definition should be from a recognized standard if legal action is going to be taken.
- guax 2y ago
  I'm lost that people keep discussing the terms in terms of vague capabilities (not suitable for low speed muddy, etc) and not focusing on the actual mechanical difference. Is it the locking differentials or not? Is that the only distinction that matters in this case? I have no clue. Would a AWD not have it by definition? Do all 4wd have it?
  - Gibbon1 2y ago
    Really you want five things if you're doing hard off road. 1. Locking differentials so all 4 tires spin in sync. 2. Extra low gears so you can crawl at a walking pace or less. 3. Clearance so you don't high side. 4. Strong suspension that won't get beat to death. 5. Tires that can take the abuse. Typical AWD's don't have 1, 2 and 4. Lack of #1 means if one tire spins you lose traction. Lack of #2 in a manual transmission means you burn out your clutch. Lack of #4 means breakdowns and helping the guy that owns your auto shop put his kid through college. You can lift AWD and put good tires on them. Tip I've heard from people that live in places like rural Nevada having a 4WD gives you the opportunity to get stuck farther in.
    - aeonik 2y ago
      Locking differentials are overrated. Computer controlled drive trains with single wheel breaking can achieve all of the same capability for less weight and money. The fact that a Subaru got cited in the article is ridiculous. This vehicle is far more capable than even some cheaper 4 wheel drive systems.
    - motohagiography 2y ago
blackeyeblitzar 2y ago
I’ve seen YouTube videos of stock Subarus handling tough trials in Moab and elsewhere. This type of distinction seems too simplistic and isn’t something that should result in threats to confiscate the vehicle or jail time.
- nofunsir 2y ago
  Agreed. There needs to be serious statistics to back up the claim that it is SO COMMON the case where one wheel off the ground and thus you're stuck -- it's SO COMMON and the effects SO CATASTROPHIC that the punishment is potentially 6 months incarceration (aka ruining most people's lives permanently). I've seen plenty of 4wd vehicles stuck for myriad reasons. How about adding vehicle weight, tire pressure, tire diameter, tire width, tread depth, tread pattern, passenger count, mandatory shovels, mandatory boards, mandatory jacks, to the law?? And to think the rangers WENT OUT OF THEIR WAY to install secret trail cams and then pour over the footage or set up some CV software to auto send such damning letters to those who dare enjoy the national park! This blows my mind. And these rangers should be ashamed of themselves.
hi_hi 2y ago
I was hoping to read the comments here to understand once and for all what the difference between AWD and 4WD is. I'm still as confused as I was before reading the comments. It appears the answer is...it depends on the manufacturer/vehicle.
- xnzakg 2y ago
  From TFA: > The most consequential distinction between AWD systems and more capable 4WD systems is that most vehicles equipped with 4WD have one or more locking differentials that massively aid in off-road traction. While AWD systems are great for increasing driver confidence on slippery road surfaces and in light off-roading, they are easily flummoxed in more challenging off-road terrain, especially low-speed and low-traction situations.
  - carabiner 2y ago
    Numerous sources saying this is wrong. 4WD is not just AWD with locking diffs. Park service should call for cars that only have locking diffs if that's what they mean.
    - deleted 2y ago
      [deleted]
  - quicklime 2y ago
    Pretty sure the Subaru Crosstrek mentioned in the article doesn't have one, but a WRX STI (also marketed as "AWD") has a lockable center diff. I agree with the other comment: if the Parks Service wants locking diffs (or ride height or whatever else) they should say so, not rely on inconsistent marketing terms.
- ip26 2y ago
  4WD mechanically interlocks the front and rear wheels (setting aside the front and rear differentials). You cannot use 4WD on clean pavement because of this; the front and rear may need to turn at different rates which 4WD doesn’t allow. It’s ok off road because the wheels can slip a little in the dirt. AWD generally does not mechanically 1:1 interlock anything, instead using things like torque converters. This allows it to be used on clean pavement. It isn’t as robust as 4WD, and has to respond to wheel slip instead of simply being 1:1 all the time.
throwaway984393 2y ago
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alvah 2y ago
Good luck making a citation stick if the vehicle has four wheels and they're all driven, i.e. 4WD
toofy 2y ago
This thread is a perfect example of why we need to reign in marketing and its insistence on misleading people. Because and only because i’ve been lingering in the off-roading community for a few years i personally understand why the NPS end goals are not only reasonable but probably necessary. but i feel terrible for the sheer number of people who have been intentionally duped by marketers. i’ve seen it repeatedly, someone buys an “all wheel drive” truck or suv, and from the initial first commercial they see all the way through to the salestrash, they were misled. over and over they end up justifiably frustrated finding out they’ve spent tens of thousands of dollars being misled on their vehicle’s capabilities only to learn their “off-road AWD” vehicle really really shouldn’t leave the suburban pavement. and that the misleading was all a ploy by marketers and their insistence on muddying the waters. this is far from limited to auto manufacturers, we see this misleading trash across the entire board. we desperately need to get back closer towards something resembling honesty in marketing.
- jokoon 2y ago
  Capitalism doesn't really reward honesty. That's why it matters to properly regulate the market.
  - spacebanana7 2y ago
    That's over simplifying. Sketching out the game theory, in markets with repeated interactions there's a great reward to honesty. A local baker wouldn't do well by giving customers food poisoning by slacking on hygiene. Even absent regulation customers would stop visiting for daily lunches after a while. However in single trade markets, there's a great temptation to be dishonest. A big city realtor selling to overseas buyers has a potentially incredible reward for being dishonest about the value of a property. And absent regulation (and enforcement) it can be very lucrative to be a liar.
    - michaelt 2y ago
      > A local baker wouldn't do well by giving customers food poisoning by slacking on hygiene. Even absent regulation customers would stop visiting for daily lunches after a while. Historically this wasn't really the case, as I understand things. Obviously if your hygiene standards were so low that every customer got ill immediately every time, that would be easily detected. But if you just overlook the occasional rat droppings in the flour sack, or put the occasional handful of sawdust to bulk out the sausage filling? So one or two customers get sick per month? And they were sickly people anyway, people in good health can shrug such things off? And every food vendor is similarly bad, so it's always plausible something else got them sick? It would be pretty hard for that to get traced back to you.
nofunsir 2y ago
PSA: Regarding the National Park system, it is now gate-kept by Booz Allen Hamilton (of McLean, VA, spooky). Yes that Booz Allen Hamilton. They made millions creating a database that keeps track of where everyone recreates[1] and make more millions auctioning off access to the parks. You thought your lottery fee on that permit you didn't get at least went to a good cause? lol. Nope. It went to Snowden's old employer. It's also convenient that the park system (and others) are conveniently NOT ACCEPTING CASH whenever it's inconvenient for them to do so. It further creeps me out that the OP never saw a single soul yet got a CCP-esque letter. This means they've also installed secret cameras, and that the Recreation.gov database perhaps has some extra tables to attach "incidents" such as this.
- nofunsir 2y ago
  [1] https://www.youtube.com/results?search_query=booz+allen+hamilton+recreation+gov https://www.youtube.com/results?search_query=booz+allen+hami...
bagels 2y ago
If you are a Subaru owner, just buy a chrome 4x4 badge on eBay.
boesboes 2y ago
The marketing department strikes again! When I was younger we made a joke about how there was 'the commission' that made everything suck more. Just to fuck with us. For instance making sure hot dogs come per 8, but buns per 6. Or the '3 person portion' with 4 equal size pieces. Or making the plastic on top of packaging so thin the 'open here' tabs will never work. Anyway, I've since learned this is actually called 'marketing departments' and that commission that makes everything suck is just emergent behavior. Probably anyway ;)
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iramiller 2y ago
The biggest missing piece in these definitions? The tires. Most cars these days come with a very highway biased tire. These tires will fail very quickly in most conditions found on off road trails, especially those that are designated as 4x4 required. Failure can be as innocuous as limited traction or complete such as a flat tire from a puncture. If you are in a situation where a tire is punctured from lack of durability how do you think that space saver spare (or can of fix-a-flat) is going to help you get out? The second major issue with AWD systems is often the clutch based systems that are engaged to transfer power ‘from the wheels that slip to the wheels that grip’. When used in demanding conditions these systems can overheat and shutdown. This also applies to brake biasing systems as well (brakes applied to spinning wheels to transfer torque to other wheels). It can be especially challenging for brakes as there is generally not sufficient air flow over the brakes to cool them during slower speed off-road travel.
mberning 2y ago
People that think the government is correct here need to watch the video of a Subaru Forster casually summiting a huge sand dune while many “proper off road vehicles” fail to do so.
jumploops 2y ago
As someone who recently purchased a 4x4 vehicle after getting stuck in an “all-wheel drive” vehicle… I can’t fault the NPS for these actions. Every manufacturer seems to have a different definition of 4WD, with the line between AWD getting blurrier and blurrier. Sure, some AWD systems are pretty capable with automatic electronic braking to drive power to different wheels (mine wasn’t). Even my new 4x4 vehicle also has this (A-trac) and I rarely need to lock my diffs, it’s great! But when push comes to shove, road conditions are unpredictable and having a high-clearance vehicle that you can manually override which wheels are getting power is a lifesaver (literally).
1970-01-01 2y ago
Completely omitted are tri and quad motor EVs, which meet both definitions of 4WD and AWD (inclusive OR).
foobarbecue 2y ago
So I have a 2015 Mitsubishi Outlander Sport, which says it has 4WD (not AWD) but from what I can tell the technology is equivalent to what Subaru et al calls AWD. Am I right about that?

131 points by rntn 2y ago

While there are rare situations where locking differentials are meaningful, having been in many hair raising off-road situations, including a real life or death one, I'd much rather have AWD and clearance, than 4WD and no clearance. That is to say, I'm not convinced by the article's hypothesis about locking diffs. It's extremely rare to need to deploy those: beached, or slow starts up vertical surfaces like boulders. An AWD vehicle with good tires and good clearance is really quite good. Bonus points if you don't care about wrecking it.

NDizzle 2y ago
What 4wd vehicle doesn’t have good ground clearance?!
- tom_ 2y ago
  First generation Subaru Justy.
- jofer 2y ago
  Most stock pickups, actually. You'd be surprised how low the clearance is on a stock f150 without the various off-road packages. I.e. you can easily have a pickup with basic 4wd but only 8 inches of ground clearance. That's technically "high clearance", but not by much, and the poor approach, departure, and break over angles make it tough too.
- ezfe 2y ago
  Subaru Impreza has less than 8 inches of ground clearance, which is the threshold they use in the link.
  - garciansmith 2y ago
    Imprezas are AWD, not 4WD, like all Subarus (well, the BRZ is RWD). The whole point of the article is that there's a difference!
- ghaff 2y ago
  Depending on your definition of "good," probably most of them. While I have been guilty of taking questionable AWD rentals on questionable roads in places like Death Valley when younger, you really want properly-equipped Jeep Rubicons and the like that you're not going to get from the average car rental place.
- COGlory 2y ago
  None, which is my point. I'm trying to say I suspect it's ground clearance, not locking differentials that matters on these roads.
  - relaxing 2y ago
    It is both.
- kube-system 2y ago
  Suzuki X-90 ?
lamp_book 2y ago
> 4WD and no clearance I think I've only really seen this as a Honda Element - otherwise I'm not sure it meaningfully exists. The reality with most AWD cars is that their important guts are hanging lower compared to 4WD trucks even when the paper ground clearance is similar. My previous car was AWD and I have a 4WD SUV now largely for off road performance, and there's no question 4WD (particularly 4LO) is much better at getting unstuck in trail conditions. The AWD is definitely superior for icy pavement in the cold months though. > Bonus points if you don't care about wrecking it This was actually what mainly pushed me over to the 4WD side instead of something like the Forester. The crossovers can actually get you to a lot of places but they do get thrashed if you do it enough. They are still more geared for pavement use but, if you're wrecking your suspension off road, the on road performance isn't gonna be great either.
- ADSSDA 2y ago
  > I think I've only really seen this as a Honda Element What Honda element had 4wd? As far as I'm aware they were all (a pretty bad) AWD system.
  - lamp_book 2y ago
    They marketed it as 4WD anyway.
- soganess 2y ago
  I'm working from memory here, but I believe early 90s Audi "quattro"s (like the 100) had the feature. That said, I think we are very much in "the exception that proves the rule" territory.
- toast0 2y ago
  > I think I've only really seen this as a Honda Element - otherwise I'm not sure it meaningfully exists. Maybe it's not meaningful, but vans in the 80s and 90s were often offered with optional 4x4, sometimes with a locking differential. An unmodified Astro or Aerostar doesn't have a whole lot of ground clearance, but could fit the definition of 4wd if properly optioned and probably wouldn't be suitable for these trails unless it gets some aftermarket help. Of course, few of these are running anymore. 4x4 kei vans can get pretty serious too, but not a lot running on US national park fire roads.
Zandikar 2y ago
> That is to say, I'm not convinced by the article's hypothesis about locking diffs. I'm not an offroader, but I did own a vehicle without a locking diff, that I later upgraded to having a locking diff (slapped a G80 on the rear of an 80's GMC Sierra) and that made a huge difference even on pavement in inclement weather. Granted, that was a RWD pickup with very little weight (typically) over the drive wheels. I'd honestly be shocked if the impact was minimal in truly offroad conditions. Granted, that's RWD which is even less than AWD or 4WD, so by no means apples to apples comparison there, just my 2 cents. That said, this isn't a binary thing (locking vs open). There's a wide variety of AWD technology out there, and I could nerd out on the specifics, but at the end of the day, some are very limited in their ability to send power to one set of wheels vs the other, and may not have locking/limited slip diffs at all, and just use brakes to prevent wheel spin. I will say, Subaru (especially the higher/sportier trims like WRX/STi) can often hang and even shame some 4WD vehicles in some conditions. There's no shortage of videos of Subarus helping a 4WD out of a jam, or completing a course they could not, but how much of that is a function of their specific AWD tech and limited slip diffs vs proper tires and lighter weight and any number of things is a matter of debate that I'm not qualified to weigh in on. Again, am a gearhead, but not an offroader. So I suspect it's not so much the Park saying "Subaru/AWD can't cut it" but rather, keeping track of which years, brands, models, trims, and/or potential optional equipment does cut it is a much more massive headache to keep track of and verify than just saying "4WD yes, everything else no", and I can't really fault them for that.
- pandaman 2y ago
  I am not an off-roader by any stretch of imagination, but I figure the AWD works like single axle drive with a simple diff on each axle i.e. if one wheel has no traction then all torque goes to that wheel and zero goes to the opposite one. I once got stuck on pretty solid pavement in a RWD car when one rear wheel hanged off a curb and lost traction, after that the car could not move as the only wheel getting torque was the one hanging off the ground. I figure the other axle would still get torque on an AWD as they usually have some kind of limited slip mid diff effect from whatever scheme they use to distribute torque between axles, but if you hanged out a wheel on each axle then an AWD vehicle would become stuck too?

davidbanham 2y ago

Locking differentials are very useful in particularly challenging terrain. Think step rough rock climbs or soft sand. For punting along an average fire trail or dirt road, though, it’s clearance, strong tyres and suspension travel that’s more important. A Subaru has none of the above. They make great cars, but they’re not an off road vehicle.

quasse 2y ago
I say this as a Jeep owner; it's ridiculous to claim that Subarus are not appropriate for punting along fire trails. The average obstacle on fire trails in the PNW is mud or large potholes, both of which a Subaru is perfectly appropriate for. A Crosstrek has 8.7in of ground clearance which is plenty compared to say, a Prius. That being said, the trail from the linked article is not an average fire road. They have genuine rock hazards, steep slick rock climbs and descents, and deep sand. I'm sure the national park service is extremely tired of people getting stuck and setting off their emergency beacons because they drove inappropriate vehicles into the park.
- barkingcat 2y ago
  the previous poster didn't say that subarus are not appropriate for fire trails, it's saying that Subaru's are not off road vehicles for "particularly challenging terrain", as in "Think step rough rock climbs or soft sand." What it does say is that for fire trails, "clearance, strong tyres and suspension travel" are more important, which the Subaru does quality for.
  - quasse 2y ago
    > it's clearance, strong tyres and suspension travel that’s more important. > A Subaru has none of the above. Maybe you and I take different meanings from the phrase "none of the above". My intended meaning was that a Subaru has "some of the above".
    - davidbanham 2y ago

chubs 2y ago

I have a new Tiguan. It’s supposed to be AWD. In reality though, even when in off-road mode, it’s basically front-wheel-drive as evidenced by the fronts spinning when you accelerate hard into a gap in traffic. Most cars that use a Haldex oem for their awd act similarly.

OrigamiPastrami 2y ago
The neat thing about the Haldex is that with just a software tune you can substantially improve the performance of it. The hardware is actually far more capable than you'd ever know with the enormous amount of slack that's programmed into it from the manufacturers. Obviously this voids your warranty, but it's a fairly low-risk modification.
- chubs 2y ago
  Ok I’m interested… how is this doable?
  - OrigamiPastrami 2y ago
    I only spent a few minutes on Google so you'd have to do your own research since I am not familiar with the Tiguan although I know the MQB platform it's built on. Anyway for the Tiguan you might have to actually order a part, there might not be enough interest in that model specifically. If you google "tiguan haldex tune" it will take you in the right direction. This tune is somewhat common for the performance cars on the MQB platform, like the Golf R and RS3. I can't think of any reason it would cause trouble for the Tiguan but it's mostly track junkies doing these modifications, not offroad enthusiasts.
SkyPuncher 2y ago
Do you have adjustable drive modes? When I put my car into sport mode, it does nearly 50/50 power application. When it’s in normal or eco, it will put 80% of the load on the front tires, then only increase rear tire load as needed.

williamstein 2y ago

"Up to six months imprisonment" for repeat offenders.

deleted 2y ago
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nofunsir 2y ago
Whatever happened to cruel and unusual?

drewg123 2y ago

I wonder what this even means in the context of EVs? Eg, some vehicles have a motor per wheel...

op00to 2y ago
The actual letter says “High clearance 4WD”. There’s more to off-roading than traction.
- leoh 2y ago
  No, off-roading is about having the right equipment that doesn’t cause other people problems or problems that you regret. If I’m on a well-graded gravel road, it should be fine to take a Ferrari on it without stupid rules getting in the way.
  - deleted 2y ago
    [deleted]
  - seattle_spring 2y ago
    These rules are not applied to "well-graded gravel roads." There are specific routes that require the specific equipment, and none of the requirements are unreasonable given the demands of the terrain.
- dag11 2y ago
  What is considered "high"? The Rivian R1T's clearance goes up to 14.9 inches, and has a motor per wheel. Does it count?
  - op00to 2y ago
    Probably? I think greater than 9” is considered high clearance, but the actual required clearance likely depends on the particular trail.
mikestew 2y ago
"Some", which is what, just Rivian? I wouldn't take our dual-motor Hyundai Ioniq 5 down anything more technical than a forest road, if only because of its (IIRC) 7 inches of ground clearance. And I imagine the AWD software is tuned to icy suburban streets, not something like this trail. Best I can tell, the AWD is supposed to get you to the ski slopes, not down the Rubicon.

ADSSDA 2y ago

As pretty much anyone who offroads knows, AWD vehicles absolutely tear up the trails vs a proper 4wd with lockers, since AWD relies on detecting tirespin (ie, destroying trail) to determine when it needs to activate.

londons_explore 2y ago
It's really just poor sensors and software. AWD can theoretically work far better than a 4WD with diff locks, because it can simulate, based on the steering wheel angle, the exact speed each wheel should turn, and 'lock' each wheel to that speed giving zero slippage. Just a shame that the sensor -> computer -> actuator feedback loop seems to be 200 milliseconds or more, so AWD vehicles just end up having different wheels slip semi-at-random till that wheel gets the brakes activated 200ms later.
- jofer 2y ago
  AWD has come a long way in that regard in the last few years. It's still highly variable from manufacturer to manufacturer, but systems that use internal clutches alongside brakes (and not only brakes) to control wheel movement + tight feedback loops can really do a great job of minimizing wheel spin. They get a lot of hate, but the bronco sport has the best AWD system I've driven to date in that regard. And with that said, it is still the type of thing the Park Service would rightfully cite as not a proper 4wd. 9ish inches of clearance is not much, and the lack of a low range will bite you. I've taken mine on plenty of milder 4wd only trails in parks (e.g. black gap in big bend plus tons and tons of forest service roads), but I'm certainly not going to do elephant hill in canyonlands with it. That's what the dedicated off-road rig is for. There are "4wd only" trails in national parks that high clearance AWD is fine on. The rangers will tell you which ones those are. Canyonlands is a different beast than most national parks. Canyonlands has some very gnarly trails open if you have a permit. Lookup dollhouse sometime. Beautiful, but insanely technical. Elephant hill is better known and a bit milder.
  - sciurus 2y ago
    > I'm certainly not going to do elephant hill in canyonlands with it Someone has, albeit with a slight lift. https://www.broncosportforum.com/forum/threads/off-roading-on-elephant-hill-trail-in-canyonlands-ut-trip-report-mods-that-mattered-most.7448/ https://www.broncosportforum.com/forum/threads/off-roading-o... From their report of "the little three-, two- and (very occasionally) one-wheel-yeet maneuver", it sounds like the lack of suspension travel was the main issue. The details of your AWD or 4WD system don't matter as much if you can keep your wheels on the ground. Still, just because they were fine doesn't mean someone else would have been. The main risk seems like doing a somewhat technical, off-the-beaten-path trail alone regardless of your vehicle's capabilities.

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olliej 2y ago

I still dont understand the difference between 4wd and awd, but the article spends more or less the entire time talking about locking and limited slip differentials and how AWD generally don’t have them which is “why they’re not allowed”, while also acknowledging that just being 4wd doesn’t mean there’s any kind of diff lock either. If the actual reason ia the difference in how the diff is locked, then access should be restricted on the basis of that, not on the mechanism the wheels are driven. I assume that the actual reason for the 4wd only rule is because there is a real difference in how they work?

barkingcat 2y ago
This article says a bit about the differences: https://www.caranddriver.com/features/a27630736/awd-vs-4wd/ https://www.caranddriver.com/features/a27630736/awd-vs-4wd/ The primary reason there's a 4WD vs AWD distinction is the ability to lock the differentials, and that determines the mechanisms that the wheels are driven by. And that's why they use those terms in a prescriptive law context. to simplify: AWD -> power gets to all wheels (driven wheels) but wheels are usually allowed to spin at different speeds to facilitate pavement driving and turning. 4WD -> power gets to all wheels, but there is a locking mechanism that locks all wheels so they all turn at the same speed - if you know the physics of turning objects, it means turning while underway is either impossible or damaging to the drivetrain. This is however, useful in mud or rock, or challenging terrain. When on mud or rock or whatnot, you turn, move a bit, stop, check, turn a bit, move, stop, check, turn a bit, movie, stop, etc. So the fact that all wheels turn at the same time is an advantage. The reason some 4WD don't have a "differential lock" is that it's fused by bare metal - it doesn't need a lock because it's welded together, so no lock needed! The car and driver article gives an easy test: if the car manual tells you "this is bad for road driving" - that's 4WD. you might think "well 4WD is terribly useless for regular driving" and you would be entirely correct. That's why most 4WD cars incorporate both modes of driving mechanisms so they can switch. You can tell apart a permanent 4WD / full time rock climber by the owner needing to use a trailer to move the vehicle instead of driving it over the highway, usually they use a pickup truck or SUV with a regular drivetrain to haul gear and pull the trailer with the 4WD vehicle to the trailhead, unload, then go into places like Death Valley Back Country or Moab with the 4WD vehicle.

i_am_jl 2y ago

Not sure about this park, but elsewhere the NPS has made this distinction clear. Death Valley's map makes clear that a high clearance crossover, high clearance 2WD or high clearance AWD vehicle is one class, and 4WD vehicles are another. See page 2: https://www.nps.gov/deva/planyourvisit/upload/508-Backcountry-and-Wilderness-Access-map_.pdf https://www.nps.gov/deva/planyourvisit/upload/508-Backcountr... EDIT: https://www.nps.gov/cany/planyourvisit/maps.htm https://www.nps.gov/cany/planyourvisit/maps.htm has a whole lot of maps for the Canyonlands and none of them make this distinction, maybe this isn't as apparent at that park.

SkyPuncher 2y ago
It was very clearly defined, but finding the definition would require you to go looking for it.
rocqua 2y ago
Notably, this marks a 4WD as having a low gearing case, ot says nothing about locked differentials.
ghaff 2y ago
The Death Valley one seems reasonable--if a bit conservative, which is appropriate. And high clearance seems an appropriate distinction--which the rangers will make as well. It's probably also worth noting that for places like the Racetrack having appropriate tires (and full-size spares) is important as well. I wouldn't have an issue driving there on my own but I wouldn't probably do it in a random rental.

leoh 2y ago

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ryandrake 2y ago

It's good that amongst the know-it-all Reddit responses typical to these kinds of education threads, the OP learned something about his or her car, and came out of the thread with a better knowledge of the differences between 4WD and AWD. One of the Redditors summed up the stupidity of these marketing terms: All Wheel Drive? Cool. There are four wheels. All of them means four. I'm sure many people's knowledge of their car ends there. The terms 4WD and AWD are as misleading as USB Full Speed vs. USB High Speed (quick, tell me which one is faster without looking it up?)

xyst 2y ago
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deleted 2y ago
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jrs235 2y ago
AWD means that all the wheels receive power from the power train. Most AWD will stop providing power to a wheel if it loses traction (spins). This is because they have an unlocked differential. 4WD typically means all four wheels can receive power from the power train and can be locked so that that will not lose power if they spin.
- falcolas 2y ago
  > AWD means that all the wheels receive power from the power train. I used to think that, until my car (Dodge Charger) with AWD had its tail swing out on ice. Basically, AWD for that vehicle meant "Rear Wheel Drive until it slips," at which point the front wheels would receive power. Same with my Toyota Prius, though it was FWD until it slipped, then the rear wheels kicked in. Even my AWD EV with dedicated motors doesn't have them all active all the time. The Subaru is the only AWD vehicle I've owned which was full time 4 wheel drive.
  - Klonoar 2y ago
    We typically refer to these as RWD-biased AWD, etc. BMW’s xDrive is a RWD biased AWD.

adrr 2y ago

Whats the difference between AWD and 4WD? Luxury SUVS are AWD and have transfer cases with locking diffs. G Wagons, Range rovers, Cayennes. The luxury crossovers have limited slip diffs and brake torque vectoring. Edit: Not sure why i am getting downvoted. Here are the specs to a G Wagon. AWD with front and rear diff locks. https://www.caranddriver.com/mercedes-benz/g-class/specs https://www.caranddriver.com/mercedes-benz/g-class/specs

SkyPuncher 2y ago
G wagon is a proper 4WD vehicle. It might be able to drive in AWD modes, but it has proper diffs to do it. There are loads of exceptions, but generally AWD vehicles have weaker or non-existent locking diffs. For example, I believe my AWD vehicle simulates locking diffs with clutch plates. Those clutches can and do slip. They’re effective at keeping the wheels “mostly locked” but not true 4WD. Further, most of the brake based torque vectoring required “slip detection” that’s only possible when a wheel spins. These systems aren’t really perfect in actually locking out motion on a free wheel. They kind of have to let them slip from time to time to check condition. These systems also tend to allow a lot of spin before they kick in - that years up roads.

avar 2y ago

With reference to previous absurd but technically correct interpretations of US national park rules[1] I'd like to suggest a way to comply with the rule in question [2], which states: High clearance four-wheel drive is required on motor vehicles travelling on [...] Take a 2WD vehicle, then bolt an extra set of wheels onto the drive axle (the tires are apparently optional). The vehicle would still need to be high-clearance. Or, if you're feeling really adventurous, just glue a set of LEGO wheels to the center of the hub. Those wheels would demonstrably have a high clearance, and comply with the rule as written. 1. https://news.ycombinator.com/item?id=36453856 https://news.ycombinator.com/item?id=36453856 2. https://www.nps.gov/cany/learn/management/compendium.htm https://www.nps.gov/cany/learn/management/compendium.htm

metaphor 2y ago
Play stupid games, win stupid prizes. > Definitions: > High Clearance Four-Wheel-Drive (4WD) Vehicles > A Jeep, sport utility vehicle (SUV), or truck type with at least 15-inch tire rims and at least eight inches of clearance from the lowest point of the frame, body, suspension, or differential to the ground. Four wheel drive vehicles have a driveshaft that can directly power each wheel at the same time and a transfer case that can shift between powering two wheel or four wheels in low or high gear. All wheel drive (AWD) vehicles do not meet this definition.
- avar 2y ago
  Just in case it's unclear, I'm not being serious here. Still, it seems to me that the wording still allows for some rules lawyering. When they say "directly power each wheel" they clearly mean the four wheels attached to the OEM axles. But I think their wording is open to arguing that it's any four "wheels" of your choosing, and now that your drive axle has two wheels on each side... The rest of the wording allows you to flip between arguing on the basis of your now-four wheel drive axle and the stock axle. After all, they're not saying "those two wheel or four wheels". Different sets of four wheels on your now six wheel car should satisfy all the criteria. However, the mention of a transfer case is a showstopper. I shouldn't have mentioned 2WD. But given the above contortions e.g. a BMW X5 with 216mm (8.7 inches) of clearance should qualify. The manufacturer obstinately insists that it's not an AWD, but "xDrive". The gear ratio of the AT even is so low that you can idle at a standstill while in gear!

olalonde 2y ago

Stupid question but why does the National Park Service care? I can't imagine people just abandon their cars when they get stuck?

3np 2y ago
"I'll get it after the weekend" Also, rentals.
kccqzy 2y ago
Creating less work for park rangers. If people drive unsuitable vehicles and get stuck, they will call emergency. That's independent of whether they abandon their cars.
akerl_ 2y ago
No, they don't abandon them: they call for help and require both government and commercial assistance to get their cars unstuck.
davidbanham 2y ago
Recovering a car from a remote area can be a big job. Not only do you need a vehicle capable of getting into and out of the spot where the first car got stuck, it might need to do so while also carrying the first car. Dragging the first car to where you can get it on to the recovery vehicle can cause significant damage to the trail. Repairing that can be a big job when you can't just drive a tip truck full of sand/gravel/rocks to the spot. It's not at all outlandish for the consequences of a stuck Subaru to pretty quickly run to "We need to contract a high lift capacity helicopter for a few days to fly in a half tonne of gravel and a repair crew". And then there's the fact that to some degree, you're endangering the people who need to come get you.
- acdha 2y ago
  > And then there's the fact that to some degree, you're endangering the people who need to come get you. This is especially true because the same kind of people who will drive somewhere out of their league are more likely to also be doing so in bad conditions with inadequate preparation so the rescue team might be rushing at night, in adverse weather, etc. A couple of people I knew who went hiking or mountain biking in the BLM land east of San Diego had stories about sharing food and water with people who’d only packed driving treats and forgot that SUVs can get stuck pretty easily no matter what the ads showed.

jasomill 2y ago

The cited regulation[1] defines a "high clearance four-wheel-drive vehicle" as A Jeep, sport utility vehicle (SUV), or truck type with at least 15-inch tire rims and at least eight inches of clearance from the lowest point of the frame, body, suspension, or differential to the ground. Four wheel drive vehicles have a driveshaft that can directly power each wheel at the same time and a transfer case that can shift between powering two wheel or four wheels in low or high gear. All wheel drive (AWD) vehicles do not meet this definition. First, note that all recent Crosstrek models have 17" wheels and minimum ground clearance of 8.7" or more, so the only potential issue is "all wheel drive". The last sentence is at best non-normative, so the actual requirements appear to be: 1. The ability to power all four wheels at once. 2. A drivetrain that includes a transfer case capable of switching between two- and four-wheel drive and, in four-wheel-drive mode, between two distinct gear ratios. In particular, the regulation says nothing about differential locks. Obviously the Crosstrek has (1), but not (2), so the citation is valid. OTOH, (2) not only excludes Subaru-style all-wheel-drive systems and AFAIK all electric vehicles, but also several full-time four-wheel drive vehicles clearly designed for off-road use, including the Toyota Land Cruiser[2] and the military-issue AM General HMMVW[3], for no other reason than the lack of a two-wheel drive mode. [1] https://www.nps.gov/cany/learn/management/compendium.htm https://www.nps.gov/cany/learn/management/compendium.htm [2] https://www.landcruiserforum.com/manuals/2024-toyota-landcruiser/OM24J1QRG.pdf#page=43 https://www.landcruiserforum.com/manuals/2024-toyota-landcru... [3] https://gear-report.com/wp-content/uploads/2017/03/Operators%20manual%20for%20the%20M998%20series%20truck.%20June%201991_TM-9-2320-280-10.pdf#page=47 https://gear-report.com/wp-content/uploads/2017/03/Operators...

davidbanham 2y ago
Definitions are hard. By that wording, any Land Cruiser outside the 70 series is forbidden because they're a full time 4WD. Nobody will argue that an 80, 100 or 200 series cruiser isn't a very capable 4WD. I don't begrudge the parks people that wrote the regulation, though. Fundamentally what they're trying to say is just "Don't be dumb, only drive the trails in a vehicle that you know is capable, and if you don't have the experience to know that you have your answer". The job of the regulation is to give them the ability to deliver an enforcement action where it's warranted. The job of the rangers is to use their judgement in a given situation, and either pull someone up or just wave hello. That's what's happened here, the system works.

thrill 2y ago

4WD is poorly defined, and the NPS shouldn't be using it, especially by trying to classify an AWD system as something of lesser capability. The SAE even recommends using the term AWD along with 8 different subclasses, none of which use the term 4WD. Jalopnik can hand-wave all they want about what the NPS "means" but the definition should be from a recognized standard if legal action is going to be taken.

guax 2y ago
I'm lost that people keep discussing the terms in terms of vague capabilities (not suitable for low speed muddy, etc) and not focusing on the actual mechanical difference. Is it the locking differentials or not? Is that the only distinction that matters in this case? I have no clue. Would a AWD not have it by definition? Do all 4wd have it?
- Gibbon1 2y ago
  Really you want five things if you're doing hard off road. 1. Locking differentials so all 4 tires spin in sync. 2. Extra low gears so you can crawl at a walking pace or less. 3. Clearance so you don't high side. 4. Strong suspension that won't get beat to death. 5. Tires that can take the abuse. Typical AWD's don't have 1, 2 and 4. Lack of #1 means if one tire spins you lose traction. Lack of #2 in a manual transmission means you burn out your clutch. Lack of #4 means breakdowns and helping the guy that owns your auto shop put his kid through college. You can lift AWD and put good tires on them. Tip I've heard from people that live in places like rural Nevada having a 4WD gives you the opportunity to get stuck farther in.
  - aeonik 2y ago
    Locking differentials are overrated. Computer controlled drive trains with single wheel breaking can achieve all of the same capability for less weight and money. The fact that a Subaru got cited in the article is ridiculous. This vehicle is far more capable than even some cheaper 4 wheel drive systems.
  - motohagiography 2y ago

blackeyeblitzar 2y ago

I’ve seen YouTube videos of stock Subarus handling tough trials in Moab and elsewhere. This type of distinction seems too simplistic and isn’t something that should result in threats to confiscate the vehicle or jail time.

nofunsir 2y ago
Agreed. There needs to be serious statistics to back up the claim that it is SO COMMON the case where one wheel off the ground and thus you're stuck -- it's SO COMMON and the effects SO CATASTROPHIC that the punishment is potentially 6 months incarceration (aka ruining most people's lives permanently). I've seen plenty of 4wd vehicles stuck for myriad reasons. How about adding vehicle weight, tire pressure, tire diameter, tire width, tread depth, tread pattern, passenger count, mandatory shovels, mandatory boards, mandatory jacks, to the law?? And to think the rangers WENT OUT OF THEIR WAY to install secret trail cams and then pour over the footage or set up some CV software to auto send such damning letters to those who dare enjoy the national park! This blows my mind. And these rangers should be ashamed of themselves.

hi_hi 2y ago

I was hoping to read the comments here to understand once and for all what the difference between AWD and 4WD is. I'm still as confused as I was before reading the comments. It appears the answer is...it depends on the manufacturer/vehicle.

xnzakg 2y ago
From TFA: > The most consequential distinction between AWD systems and more capable 4WD systems is that most vehicles equipped with 4WD have one or more locking differentials that massively aid in off-road traction. While AWD systems are great for increasing driver confidence on slippery road surfaces and in light off-roading, they are easily flummoxed in more challenging off-road terrain, especially low-speed and low-traction situations.
- carabiner 2y ago
  Numerous sources saying this is wrong. 4WD is not just AWD with locking diffs. Park service should call for cars that only have locking diffs if that's what they mean.
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- quicklime 2y ago
  Pretty sure the Subaru Crosstrek mentioned in the article doesn't have one, but a WRX STI (also marketed as "AWD") has a lockable center diff. I agree with the other comment: if the Parks Service wants locking diffs (or ride height or whatever else) they should say so, not rely on inconsistent marketing terms.
ip26 2y ago
4WD mechanically interlocks the front and rear wheels (setting aside the front and rear differentials). You cannot use 4WD on clean pavement because of this; the front and rear may need to turn at different rates which 4WD doesn’t allow. It’s ok off road because the wheels can slip a little in the dirt. AWD generally does not mechanically 1:1 interlock anything, instead using things like torque converters. This allows it to be used on clean pavement. It isn’t as robust as 4WD, and has to respond to wheel slip instead of simply being 1:1 all the time.

throwaway984393 2y ago

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alvah 2y ago

Good luck making a citation stick if the vehicle has four wheels and they're all driven, i.e. 4WD

toofy 2y ago

This thread is a perfect example of why we need to reign in marketing and its insistence on misleading people. Because and only because i’ve been lingering in the off-roading community for a few years i personally understand why the NPS end goals are not only reasonable but probably necessary. but i feel terrible for the sheer number of people who have been intentionally duped by marketers. i’ve seen it repeatedly, someone buys an “all wheel drive” truck or suv, and from the initial first commercial they see all the way through to the salestrash, they were misled. over and over they end up justifiably frustrated finding out they’ve spent tens of thousands of dollars being misled on their vehicle’s capabilities only to learn their “off-road AWD” vehicle really really shouldn’t leave the suburban pavement. and that the misleading was all a ploy by marketers and their insistence on muddying the waters. this is far from limited to auto manufacturers, we see this misleading trash across the entire board. we desperately need to get back closer towards something resembling honesty in marketing.

jokoon 2y ago
Capitalism doesn't really reward honesty. That's why it matters to properly regulate the market.
- spacebanana7 2y ago
  That's over simplifying. Sketching out the game theory, in markets with repeated interactions there's a great reward to honesty. A local baker wouldn't do well by giving customers food poisoning by slacking on hygiene. Even absent regulation customers would stop visiting for daily lunches after a while. However in single trade markets, there's a great temptation to be dishonest. A big city realtor selling to overseas buyers has a potentially incredible reward for being dishonest about the value of a property. And absent regulation (and enforcement) it can be very lucrative to be a liar.
  - michaelt 2y ago
    > A local baker wouldn't do well by giving customers food poisoning by slacking on hygiene. Even absent regulation customers would stop visiting for daily lunches after a while. Historically this wasn't really the case, as I understand things. Obviously if your hygiene standards were so low that every customer got ill immediately every time, that would be easily detected. But if you just overlook the occasional rat droppings in the flour sack, or put the occasional handful of sawdust to bulk out the sausage filling? So one or two customers get sick per month? And they were sickly people anyway, people in good health can shrug such things off? And every food vendor is similarly bad, so it's always plausible something else got them sick? It would be pretty hard for that to get traced back to you.

nofunsir 2y ago

PSA: Regarding the National Park system, it is now gate-kept by Booz Allen Hamilton (of McLean, VA, spooky). Yes that Booz Allen Hamilton. They made millions creating a database that keeps track of where everyone recreates[1] and make more millions auctioning off access to the parks. You thought your lottery fee on that permit you didn't get at least went to a good cause? lol. Nope. It went to Snowden's old employer. It's also convenient that the park system (and others) are conveniently NOT ACCEPTING CASH whenever it's inconvenient for them to do so. It further creeps me out that the OP never saw a single soul yet got a CCP-esque letter. This means they've also installed secret cameras, and that the Recreation.gov database perhaps has some extra tables to attach "incidents" such as this.

nofunsir 2y ago
[1] https://www.youtube.com/results?search_query=booz+allen+hamilton+recreation+gov https://www.youtube.com/results?search_query=booz+allen+hami...

bagels 2y ago

If you are a Subaru owner, just buy a chrome 4x4 badge on eBay.

boesboes 2y ago

The marketing department strikes again! When I was younger we made a joke about how there was 'the commission' that made everything suck more. Just to fuck with us. For instance making sure hot dogs come per 8, but buns per 6. Or the '3 person portion' with 4 equal size pieces. Or making the plastic on top of packaging so thin the 'open here' tabs will never work. Anyway, I've since learned this is actually called 'marketing departments' and that commission that makes everything suck is just emergent behavior. Probably anyway ;)

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iramiller 2y ago

The biggest missing piece in these definitions? The tires. Most cars these days come with a very highway biased tire. These tires will fail very quickly in most conditions found on off road trails, especially those that are designated as 4x4 required. Failure can be as innocuous as limited traction or complete such as a flat tire from a puncture. If you are in a situation where a tire is punctured from lack of durability how do you think that space saver spare (or can of fix-a-flat) is going to help you get out? The second major issue with AWD systems is often the clutch based systems that are engaged to transfer power ‘from the wheels that slip to the wheels that grip’. When used in demanding conditions these systems can overheat and shutdown. This also applies to brake biasing systems as well (brakes applied to spinning wheels to transfer torque to other wheels). It can be especially challenging for brakes as there is generally not sufficient air flow over the brakes to cool them during slower speed off-road travel.

mberning 2y ago

People that think the government is correct here need to watch the video of a Subaru Forster casually summiting a huge sand dune while many “proper off road vehicles” fail to do so.

jumploops 2y ago

As someone who recently purchased a 4x4 vehicle after getting stuck in an “all-wheel drive” vehicle… I can’t fault the NPS for these actions. Every manufacturer seems to have a different definition of 4WD, with the line between AWD getting blurrier and blurrier. Sure, some AWD systems are pretty capable with automatic electronic braking to drive power to different wheels (mine wasn’t). Even my new 4x4 vehicle also has this (A-trac) and I rarely need to lock my diffs, it’s great! But when push comes to shove, road conditions are unpredictable and having a high-clearance vehicle that you can manually override which wheels are getting power is a lifesaver (literally).

1970-01-01 2y ago

Completely omitted are tri and quad motor EVs, which meet both definitions of 4WD and AWD (inclusive OR).

foobarbecue 2y ago

So I have a 2015 Mitsubishi Outlander Sport, which says it has 4WD (not AWD) but from what I can tell the technology is equivalent to what Subaru et al calls AWD. Am I right about that?