8 ms·

Snow-land wants to know: Front-wheel drive, ever? I'm not driving rear-only, ever. Did that once, not again. I'm not paying another $11,000 to get the dual-mo

Snow-land wants to know: Front-wheel drive, ever? I'm not driving rear-only, ever. Did that once, not again. I'm not paying another $11,000 to get the dual-motor version when all I care about is the front. That's a whole 'nother car worth of money. Keep on building California cars, Elon. I'll buy one as soon as it fits both my budget and my climate. Some models fit one or the other, but nothing does both.

ramenmeal 8y ago
Interesting point. This should actually be an advantage for Tesla as the engineering and manufacturing costs would be much lower to produce front, rear and all wheel drive options than a traditional ICE car. I'm guessing they're hoping people buy the dual motor option for this scenario though.
- fingerlocks 8y ago
  Why would the costs be lower? Honest question. On an ICE vehicle the only difference between rear and all wheel drive is a differential and a drive shaft. Maybe I don’t know enough about electric vehicles, but “dual motor” sounds a lot more expensive.
  - londons_explore 8y ago
    Big electric motors are actually pretty cheap. They've existed in industry for over a century, and their manufacture is entirely automated. The raw materials cost of two motors each with half the power matches that of one motor. The motor controllers are probably the more expensive part, although most of the cost there is engineering design cost (much of industry doesn't use fancy motor controllers needed for a car, and cars use high power MOSFETs which are rapidly evolving tech). Tesla designing them in house will eliminate much of the cost over enough volume.
  - pedrocr 8y ago
    > On an ICE vehicle the only difference between rear and all wheel drive is a differential and a drive shaft. You need three differentials for AWD as you first need to split the power front/back and then right/left in each axle. That's two more differentials than in just RWD or FWD. You also need to package all that together with a gearbox. That's why many manufacturers don't even offer an AWD option, and having both FWD and RWD versions of a car is very rare if it happens at all. Meanwhile Tesla already builds all their cars to have two independent motors front/back each with their differential. They could very easily build a FWD car right now just by omitting the rear assembly. The cars are apparently even already designed to work with just the front motor for reliability so even the software update would be simple. And building AWD cars by having two electric motors is almost surely not more expensive than the ICE way. Electric motors are much simpler than combustion ones and you eliminate all the mechanical parts needed to split the power between the axles. Control also becomes much better as the software gets to adjust power independently to both axles.
    - dsfyu404ed 8y ago
      >And building AWD cars by having two electric motors is almost surely not more expensive than the ICE way. You need a differential for each driven axle. The expense of the extra motor and motor controller vs the expense of the transfer case (or FWD based equivalent), and drive shaft (not really all that expensive) is probably close to a wash or slightly in favor of the ICE vehicle. I don't think you understand how cheap and commoditized drive-train parts are. Like really, these assemblies are cheap and almost go together like legos (from an OEM perspective). It's not like you burn tons of engineering hours making a FWD or RWD vehicle into AWD so long as whatever floor pan you're working with was designed to be AWD compatible.
      - pedrocr 8y ago
        Thinking about it some more, maybe in a mass produced ICE AWD can indeed be a cheaper add-on. Something like a Subaru that does AWD for all cars. I was thinking more of the direct Tesla competitors that tend to charge quite a bit for AWD as an extra. But it's hard to compare from the outside as adding AWD to a car is often associated with different trim levels too. Someone like Sandy Munro that does detailed costing would be able to answer this definitively for a few models. But it will most likely depend on the actual implementation to see what ends up cheaper. According to Munro Tesla has a big advantage in the cost, weight and performance of the motors right now compared to other EVs so that might be enough to tip the scale. I'd love actual data though.
- sliken 8y ago
  Well there's a few problems with that. First of all FWD saves money, complexity, and weight on an ICE car because you avoid a long drive shaft, and you can mount the engine transversely which is more compact. You also get more interior room in the car since there's no hump for the drive shaft. With an electric car you don't save anything with RWD vs FWD, you end up with poorer steering, poorer acceleration, and worse hill climbing, especially if it's snowy or icy. Nor is it cheaper to produce. As a result even electric cars intended for city use like the BMW i3 and Renault have RWD. On the model 3 the rear motor is larger and a permanent magnet motor (which is more efficient) and the front motor is an induction motor. So a FWD would have less power than the RWD, and it would also have less range than the RWD. Not sure Tesla would want to try to sell a car slower (because FWD), slower (because of less HP), and with less range (because of efficiency) without it being cheaper to produce.... just to have a FWD.
colechristensen 8y ago
Silicon Valley transport tech needs to visit the north some time. There is going to be a very rude awakening when everyone realizes their machine learning models only handle light rain in the southwest.
- CamperBob2 8y ago
  Don't they sell a ton of Teslas in Norway?
  - riffraff 8y ago
    they do, due to subsidies and high income.
- dmix 8y ago
  Literally every time self driving cars are brought snow and rain are mentioned as a necessary step for wide deployment. They were aware of this problem even in the 1990s.
  - riffraff 8y ago
    software engineers are aware of <DST, weird person names, malicious users, 4-byte UTF characters etc> yet they still write software that doesn't handle them well. The fact that people abstractly know a situation exists does not mean they will handle it correctly. Also, remember the issues with "racist" face recognition systems that were trained on non-diverse data sets? It's not like google engineers forgot black people exist, but I think it's not trivial to pay the proper attention to some problems if they are outside of your daily experience.
kolinko 8y ago
Hm, on the website it says that there is an all-wheel drive version just 10-15% more expensive ($4-$5k).
- tapland 8y ago
  I was going to correct you on what 10-15% of the sales price was, but then I noticed that yes, it is 50% more expensive here from Sweden. The US price is not that bad!
Drunk_Engineer 8y ago
You realize the Tesla does not have a heavy engine in the front? The term FWD is meaningless here.
- kibibu 8y ago
  It means the power is applied to the front wheels, not the back. Youre thinking of front/mid/rear engine.
- pasta 8y ago
  You must be a drunk engineer. It's about pulling or pushing the car. When it snows all BMWs get stuck here.
  - jammur 8y ago
    The difference is that a traditional RWD car has a heavy engine in the front, but is being pushed from the back where none of the weight is. So lack of traction and fish tailing is the obvious result. However, I think a RWD electric car would have less problems with traction (and thus, fish tailing), since the weight is distributed over the length of the car more evenly. I think push vs pull is legit, but I don't think it would be as much of a problem when all the weight isn't in the front. I'd be interested to hear from some Tesla owners who drive RWD in the snow.
    - ivan1783 8y ago
      Not really...check weight distributions for any modern vehicle, you will find the majority of the competent manufacturers get it right around 50/50 front/back. Meaning your FWD Honda has no advantage over a RWD BMW except for the tendency for the Honda to understeer and the BMW to oversteer. This is the main problem in less than ideal traction conditions...
      - petersellers 8y ago
        Define "competent manufacturer". I'd be willing to wager that most front wheel drive sedans sold in the US are closer to 60/40, not 50/50. Pickup trucks (very popular in the US) also have a weight distribution much more skewed to the front. 50/50 distribution is more common for sports cars sure but that is not the majority of cars sold.
fingerlocks 8y ago
I prefer to have an optional locking differential on the drive wheels for snow. In my experience, the most common problem with snow is getting enough traction to move out of parking spot or up a steep incline. Like most AWD vehicles, the AWD Tesla has an open differential which does not help much in these scenarios. When traction gets dicey it behaves like a 2WD with torque spread between one front and one rear wheel.
- imeron 8y ago
  It has a diff-like behavior by actively braking the wheels from software. See Youtube video https://youtu.be/xbaNQQaFrnE https://youtu.be/xbaNQQaFrnE
  - fingerlocks 8y ago
    Thanks! My side hobby is restoring & retrofitting 80s vehicles, so I had not considered new tech like this. I just assumed it worked like every other open diff.
    - pedrocr 8y ago
      That's how every other open-diff car already works. Everyone does that. EVs just have the extra advantage that they're much more precise at applying power so the traction control can be much better.
      - fingerlocks 8y ago
        I was referring to the brake based traction control system, not the differential
        pedrocr 8y ago
        That's also what I mean of course. All modern AWD systems and even just FWD/RWD cars use the ABS to do traction control with open-diffs. The base AWD system in a Subaru is three open-diffs and then ABS braking is used on any wheel that's slipping to make sure the torque still reaches the other wheels.
sliken 8y ago
FWD has a reputation for being good in the snow, I grew up with a FWD Saab that was pretty awesome in the snow. Mostly because it had tall narrow tires, FWD, and well over 60% of the car's weight over the front wheels. However RWD is actually better... assuming the car has a good front/rear balance near 50%... like the Telsa. Any FWD gets LESS traction when climbing than driving on the flats. A RWD gets MORE traction when climbing than driving on the flats. Of course when driving down hills you can always throttle off and just use the brakes. Additionally your limited traction budget in a RWD allows the front wheels to be dedicated to steering only. On a FWD you have to spend part of your traction budget on acceleration. So get the RWD, it's cheaper than AWD, and better in the snow than FWD.
- lagadu 8y ago
  The problem is the tendency to fishtail on long, light corners, nothing to do with going up or downhill.
  - sliken 8y ago
    Oversteer (RWD without enough traction) and understeer (FWD without enough traction) are two sides of the same coin. Personally I'd rather have oversteer, which is easily compensated for (a bit of steering and let off the throttle), but doesn't impact your path around the corner. It's also quite fun. Understeer on the other hand does impact your path around the corner, the car plows straight ahead as you ask too much of it. Additionally the threshold for understeer is lower since it's the front tires trying to handle acceleration and steering. So a RWD has more traction at a given speed than FWD. Keep in mind that the that RWD in terrible in the snow comes from things like empty pick up trucks (no weight on the rear wheels) or old American sedans and sports cars that had large engines in the front and not much weight out back. Generally even with a perfect 50/50 weight distribution that the RWD is going to have the advantage.
    - dragontamer 8y ago
      I've always seen it as a thing of habit. If you're used to understeer (FWD loss of traction), then for safety reasons, you should stick to understeer. If you're used to oversteer, then stick with oversteer. Its not like it snows every day. Your opportunities to practice loss of traction are few and far in between.
jakobegger 8y ago
You can just put sand bags in the trunk in winter :) My parents used to do that so they could drive our Toyota Hiace in winter. As a bonus, there's fresh sand for the sandbox every spring!
- Justen 8y ago
  You also use the sand when your tires are stuck in the snow.
audunw 8y ago
RWD EV is probably better than FWD ICE. They'll generally have better weight distribution and the fine-grained control over the torque is better. Anyway, if grip is important, you might as well go for AWD. The difference from RWD to FWD is tiny, if any (I also live in snowy-lands and have driven both). But going to AWD, especially with the dual motor AWD you get with EVs, is a world of difference and probably worth the upgrade.
- justtopost 8y ago
  Having driven both, fwd ice is way better in the snow.
eemil 8y ago
Not an issue in this day and age, IMO. While FWD is more controllable, and safer in the snow, modern stability control systems have done a _lot_ to bridge the gap. My 2006 era RWD car has the manufacturer's optional stability control, and I'm constantly impressed by how effectively it keeps the car in-line in snow. Even on long, sweeping turns, where it's hard to know when you're beginning to slide. This is without any kind of steering control, with only engine power limiting and individual-wheel braking. Much more important, is to have proper tires for the season. Even if you don't experience snow, you need tires with the appropriate temperature ratings. Summer tires will turn rock-hard in freezing temperatures, and lose a lot of grip. Even on bare pavement.
bryanlarsen 8y ago
I bet RWD drive cars have fewer fatalities in the snow than AWD drive cars do. While their ability to go forward is much better, their ability to stop is very similar. I see lots of SUVs driving stupid fast on snow.
JustSomeNobody 8y ago
I'm from and in Florida and have never driven in ice or snow. Why not just call an uber on snow days? :)

ramenmeal 8y ago

Interesting point. This should actually be an advantage for Tesla as the engineering and manufacturing costs would be much lower to produce front, rear and all wheel drive options than a traditional ICE car. I'm guessing they're hoping people buy the dual motor option for this scenario though.

fingerlocks 8y ago
Why would the costs be lower? Honest question. On an ICE vehicle the only difference between rear and all wheel drive is a differential and a drive shaft. Maybe I don’t know enough about electric vehicles, but “dual motor” sounds a lot more expensive.
- londons_explore 8y ago
  Big electric motors are actually pretty cheap. They've existed in industry for over a century, and their manufacture is entirely automated. The raw materials cost of two motors each with half the power matches that of one motor. The motor controllers are probably the more expensive part, although most of the cost there is engineering design cost (much of industry doesn't use fancy motor controllers needed for a car, and cars use high power MOSFETs which are rapidly evolving tech). Tesla designing them in house will eliminate much of the cost over enough volume.
- pedrocr 8y ago
  > On an ICE vehicle the only difference between rear and all wheel drive is a differential and a drive shaft. You need three differentials for AWD as you first need to split the power front/back and then right/left in each axle. That's two more differentials than in just RWD or FWD. You also need to package all that together with a gearbox. That's why many manufacturers don't even offer an AWD option, and having both FWD and RWD versions of a car is very rare if it happens at all. Meanwhile Tesla already builds all their cars to have two independent motors front/back each with their differential. They could very easily build a FWD car right now just by omitting the rear assembly. The cars are apparently even already designed to work with just the front motor for reliability so even the software update would be simple. And building AWD cars by having two electric motors is almost surely not more expensive than the ICE way. Electric motors are much simpler than combustion ones and you eliminate all the mechanical parts needed to split the power between the axles. Control also becomes much better as the software gets to adjust power independently to both axles.
  - dsfyu404ed 8y ago
    >And building AWD cars by having two electric motors is almost surely not more expensive than the ICE way. You need a differential for each driven axle. The expense of the extra motor and motor controller vs the expense of the transfer case (or FWD based equivalent), and drive shaft (not really all that expensive) is probably close to a wash or slightly in favor of the ICE vehicle. I don't think you understand how cheap and commoditized drive-train parts are. Like really, these assemblies are cheap and almost go together like legos (from an OEM perspective). It's not like you burn tons of engineering hours making a FWD or RWD vehicle into AWD so long as whatever floor pan you're working with was designed to be AWD compatible.
    - pedrocr 8y ago
      Thinking about it some more, maybe in a mass produced ICE AWD can indeed be a cheaper add-on. Something like a Subaru that does AWD for all cars. I was thinking more of the direct Tesla competitors that tend to charge quite a bit for AWD as an extra. But it's hard to compare from the outside as adding AWD to a car is often associated with different trim levels too. Someone like Sandy Munro that does detailed costing would be able to answer this definitively for a few models. But it will most likely depend on the actual implementation to see what ends up cheaper. According to Munro Tesla has a big advantage in the cost, weight and performance of the motors right now compared to other EVs so that might be enough to tip the scale. I'd love actual data though.
sliken 8y ago
Well there's a few problems with that. First of all FWD saves money, complexity, and weight on an ICE car because you avoid a long drive shaft, and you can mount the engine transversely which is more compact. You also get more interior room in the car since there's no hump for the drive shaft. With an electric car you don't save anything with RWD vs FWD, you end up with poorer steering, poorer acceleration, and worse hill climbing, especially if it's snowy or icy. Nor is it cheaper to produce. As a result even electric cars intended for city use like the BMW i3 and Renault have RWD. On the model 3 the rear motor is larger and a permanent magnet motor (which is more efficient) and the front motor is an induction motor. So a FWD would have less power than the RWD, and it would also have less range than the RWD. Not sure Tesla would want to try to sell a car slower (because FWD), slower (because of less HP), and with less range (because of efficiency) without it being cheaper to produce.... just to have a FWD.

colechristensen 8y ago

Silicon Valley transport tech needs to visit the north some time. There is going to be a very rude awakening when everyone realizes their machine learning models only handle light rain in the southwest.

CamperBob2 8y ago
Don't they sell a ton of Teslas in Norway?
- riffraff 8y ago
  they do, due to subsidies and high income.
dmix 8y ago
Literally every time self driving cars are brought snow and rain are mentioned as a necessary step for wide deployment. They were aware of this problem even in the 1990s.
- riffraff 8y ago
  software engineers are aware of <DST, weird person names, malicious users, 4-byte UTF characters etc> yet they still write software that doesn't handle them well. The fact that people abstractly know a situation exists does not mean they will handle it correctly. Also, remember the issues with "racist" face recognition systems that were trained on non-diverse data sets? It's not like google engineers forgot black people exist, but I think it's not trivial to pay the proper attention to some problems if they are outside of your daily experience.

kolinko 8y ago

Hm, on the website it says that there is an all-wheel drive version just 10-15% more expensive ($4-$5k).

tapland 8y ago
I was going to correct you on what 10-15% of the sales price was, but then I noticed that yes, it is 50% more expensive here from Sweden. The US price is not that bad!

Drunk_Engineer 8y ago

You realize the Tesla does not have a heavy engine in the front? The term FWD is meaningless here.

kibibu 8y ago
It means the power is applied to the front wheels, not the back. Youre thinking of front/mid/rear engine.
pasta 8y ago
You must be a drunk engineer. It's about pulling or pushing the car. When it snows all BMWs get stuck here.
- jammur 8y ago
  The difference is that a traditional RWD car has a heavy engine in the front, but is being pushed from the back where none of the weight is. So lack of traction and fish tailing is the obvious result. However, I think a RWD electric car would have less problems with traction (and thus, fish tailing), since the weight is distributed over the length of the car more evenly. I think push vs pull is legit, but I don't think it would be as much of a problem when all the weight isn't in the front. I'd be interested to hear from some Tesla owners who drive RWD in the snow.
  - ivan1783 8y ago
    Not really...check weight distributions for any modern vehicle, you will find the majority of the competent manufacturers get it right around 50/50 front/back. Meaning your FWD Honda has no advantage over a RWD BMW except for the tendency for the Honda to understeer and the BMW to oversteer. This is the main problem in less than ideal traction conditions...
    - petersellers 8y ago
      Define "competent manufacturer". I'd be willing to wager that most front wheel drive sedans sold in the US are closer to 60/40, not 50/50. Pickup trucks (very popular in the US) also have a weight distribution much more skewed to the front. 50/50 distribution is more common for sports cars sure but that is not the majority of cars sold.

fingerlocks 8y ago

I prefer to have an optional locking differential on the drive wheels for snow. In my experience, the most common problem with snow is getting enough traction to move out of parking spot or up a steep incline. Like most AWD vehicles, the AWD Tesla has an open differential which does not help much in these scenarios. When traction gets dicey it behaves like a 2WD with torque spread between one front and one rear wheel.

imeron 8y ago
It has a diff-like behavior by actively braking the wheels from software. See Youtube video https://youtu.be/xbaNQQaFrnE https://youtu.be/xbaNQQaFrnE
- fingerlocks 8y ago
  Thanks! My side hobby is restoring & retrofitting 80s vehicles, so I had not considered new tech like this. I just assumed it worked like every other open diff.
  - pedrocr 8y ago
    That's how every other open-diff car already works. Everyone does that. EVs just have the extra advantage that they're much more precise at applying power so the traction control can be much better.
    - fingerlocks 8y ago
      I was referring to the brake based traction control system, not the differential
      - pedrocr 8y ago
        That's also what I mean of course. All modern AWD systems and even just FWD/RWD cars use the ABS to do traction control with open-diffs. The base AWD system in a Subaru is three open-diffs and then ABS braking is used on any wheel that's slipping to make sure the torque still reaches the other wheels.

sliken 8y ago

FWD has a reputation for being good in the snow, I grew up with a FWD Saab that was pretty awesome in the snow. Mostly because it had tall narrow tires, FWD, and well over 60% of the car's weight over the front wheels. However RWD is actually better... assuming the car has a good front/rear balance near 50%... like the Telsa. Any FWD gets LESS traction when climbing than driving on the flats. A RWD gets MORE traction when climbing than driving on the flats. Of course when driving down hills you can always throttle off and just use the brakes. Additionally your limited traction budget in a RWD allows the front wheels to be dedicated to steering only. On a FWD you have to spend part of your traction budget on acceleration. So get the RWD, it's cheaper than AWD, and better in the snow than FWD.

lagadu 8y ago
The problem is the tendency to fishtail on long, light corners, nothing to do with going up or downhill.
- sliken 8y ago
  Oversteer (RWD without enough traction) and understeer (FWD without enough traction) are two sides of the same coin. Personally I'd rather have oversteer, which is easily compensated for (a bit of steering and let off the throttle), but doesn't impact your path around the corner. It's also quite fun. Understeer on the other hand does impact your path around the corner, the car plows straight ahead as you ask too much of it. Additionally the threshold for understeer is lower since it's the front tires trying to handle acceleration and steering. So a RWD has more traction at a given speed than FWD. Keep in mind that the that RWD in terrible in the snow comes from things like empty pick up trucks (no weight on the rear wheels) or old American sedans and sports cars that had large engines in the front and not much weight out back. Generally even with a perfect 50/50 weight distribution that the RWD is going to have the advantage.
  - dragontamer 8y ago
    I've always seen it as a thing of habit. If you're used to understeer (FWD loss of traction), then for safety reasons, you should stick to understeer. If you're used to oversteer, then stick with oversteer. Its not like it snows every day. Your opportunities to practice loss of traction are few and far in between.

jakobegger 8y ago

You can just put sand bags in the trunk in winter :) My parents used to do that so they could drive our Toyota Hiace in winter. As a bonus, there's fresh sand for the sandbox every spring!

Justen 8y ago
You also use the sand when your tires are stuck in the snow.

audunw 8y ago

RWD EV is probably better than FWD ICE. They'll generally have better weight distribution and the fine-grained control over the torque is better. Anyway, if grip is important, you might as well go for AWD. The difference from RWD to FWD is tiny, if any (I also live in snowy-lands and have driven both). But going to AWD, especially with the dual motor AWD you get with EVs, is a world of difference and probably worth the upgrade.

justtopost 8y ago
Having driven both, fwd ice is way better in the snow.

eemil 8y ago

Not an issue in this day and age, IMO. While FWD is more controllable, and safer in the snow, modern stability control systems have done a _lot_ to bridge the gap. My 2006 era RWD car has the manufacturer's optional stability control, and I'm constantly impressed by how effectively it keeps the car in-line in snow. Even on long, sweeping turns, where it's hard to know when you're beginning to slide. This is without any kind of steering control, with only engine power limiting and individual-wheel braking. Much more important, is to have proper tires for the season. Even if you don't experience snow, you need tires with the appropriate temperature ratings. Summer tires will turn rock-hard in freezing temperatures, and lose a lot of grip. Even on bare pavement.

bryanlarsen 8y ago

I bet RWD drive cars have fewer fatalities in the snow than AWD drive cars do. While their ability to go forward is much better, their ability to stop is very similar. I see lots of SUVs driving stupid fast on snow.

JustSomeNobody 8y ago

I'm from and in Florida and have never driven in ice or snow. Why not just call an uber on snow days? :)