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I think the AWD helps a lot more with starting out. My old FWD car (no snow tires) would not be able to stop at a stop light that was on an incline and then st

I think the AWD helps a lot more with starting out. My old FWD car (no snow tires) would not be able to stop at a stop light that was on an incline and then start again without spinning the tires forever. The same thing with my Subaru (AT tires) and there’s no slip at all.

jeffbee 6y ago
FWD cars can't start on an incline in the rain, either. It's just a fundamental problem of that architecture. Electronic traction control can help somewhat.
grecy 6y ago
Absolutely correct, though how many accidents occur because a vehicle can't get going? (hint: none) In winter situations, it's stopping (and steering) you need to worry about, not going. (Said as someone who drives a BIG 4x4 with excellent winter tires in a part of Canada where they are required by law)
- sliken 6y ago
  None? Seen plenty of FWD stuck at the bottom of a hill that an AWD can climb. As you might imagine hanging out at the bottom of a hill is a great way to get hit.
  - grecy 6y ago
    The only crashes were stationary vehicles get hit are because the vehicle that hits them can't stop.
    - sliken 6y ago
      Right. Just what you get when it's hilly, slippery, and you have a bunch of FWD that can't climb.
throwaway0a5e 6y ago
It helps a ton any time you have to touch slush. Which is often. People aren't stupid. There's a reason why everyone who can swing it buys an AWD to commute and not everyone buys snow tires. The snow tire is still gonna be slush-o-planing any time you go onto highway slush of appreciable depth. Heck a mud tire with big fat grooves is your best bet when the tire is on that. There is no tire (suitable for general use, I'm sure the Florida mud racing crowd has something up their sleeve) that can handle that without planing. There just isn't enough space between the tread blocks for all that viscous fluid to be forced through (assuming you're going like 20+mph) and you end up on top of it. Being able to change lanes and enter traffic from side streets/driveways with less slip is just a soooooo much better experience than not being able to do those things gracefully but in exchange for a slightly a better worst case stopping distance in fairly rare conditions (ice and fresh powder). Commuting in snow is nothing like those commercials where they drive on ice. All the traction in the world won't help you when your problem is that the tire isn't making contact with the road. Driving on ice and fresh powder are so rare it's no surprise that consumers don't optimize for that. Sure you can put snow tires on your AWD but the lions share of improvement in the conditions people actually encounter comes from AWD.
- ip26 6y ago
  You don't actually have to touch the pavement. Deep, aggressive, self-clearing tread seems to be enough. I put an ice spiker pro on my bike and slush goes from ice rink to no big deal, whether or not I touch pavement. I speculate most snow & slush under compression has some shear strength to offer even though there is little dry friction.
  - snuxoll 6y ago
    The weight of your vehicle and heat in your tires (plus the heat generated by friction) causes slush, snow and light ice to melt. If your tires have aggressive enough treads they are just pushing the water away and making contact with the road surface. If conditions are bad enough to cause a FWD or RWD car to hydroplane then there’s nothing AWD can do to help it given the same tires. Grip is all that matters when it comes to staying put on the road, and that comes entirely from your tires on normal road cars (most road cars aerodynamic profiles generate lift rather than downforce, so you aren’t getting any aero grip unless you are driving a sports/supercar with aero elements).
Gibbon1 6y ago
AWD helps when you're under load going around a corner because the traction is distributed over four tires not just two. And AWD cars tend to have better weight balance. I've also noticed when driving AWD cars on sand and dirt they are stable at higher speeds than FWD.
- snuxoll 6y ago
  Traction (mechanical grip) is always distributed among four tires according to physics of center of mass, velocity and angle of travel - AWD does not change that. That said, AWD will let you put power down earlier into a corner because the extra drive wheels will help you change your angular momentum without sending you straight into a slide - but you also put extra lateral load onto your tires doing this so it's best to continue to drive like you just have RWD.
  - Gibbon1 6y ago
    You're treating lateral forces and traction forces as independent variables.
    - snuxoll 6y ago
      Absolutely not, you can’t change direction without grip - angular momentum and weight are what cause lateral loads, after all. The thing is, AWD makes it easier to get going by letting you put engine torque through all four tires. The same set of tires has the same mechanical grip regardless of how many wheels are driven, so if a FWD car would spin taking a corner at X speed due to lateral load so will your AWD car (and the AWD will have an easier time doing it).
      - Gibbon1 6y ago
        Again: You're treating lateral forces and traction forces as independent variables.

jeffbee 6y ago

FWD cars can't start on an incline in the rain, either. It's just a fundamental problem of that architecture. Electronic traction control can help somewhat.

grecy 6y ago

Absolutely correct, though how many accidents occur because a vehicle can't get going? (hint: none) In winter situations, it's stopping (and steering) you need to worry about, not going. (Said as someone who drives a BIG 4x4 with excellent winter tires in a part of Canada where they are required by law)

sliken 6y ago
None? Seen plenty of FWD stuck at the bottom of a hill that an AWD can climb. As you might imagine hanging out at the bottom of a hill is a great way to get hit.
- grecy 6y ago
  The only crashes were stationary vehicles get hit are because the vehicle that hits them can't stop.
  - sliken 6y ago
    Right. Just what you get when it's hilly, slippery, and you have a bunch of FWD that can't climb.

throwaway0a5e 6y ago

It helps a ton any time you have to touch slush. Which is often. People aren't stupid. There's a reason why everyone who can swing it buys an AWD to commute and not everyone buys snow tires. The snow tire is still gonna be slush-o-planing any time you go onto highway slush of appreciable depth. Heck a mud tire with big fat grooves is your best bet when the tire is on that. There is no tire (suitable for general use, I'm sure the Florida mud racing crowd has something up their sleeve) that can handle that without planing. There just isn't enough space between the tread blocks for all that viscous fluid to be forced through (assuming you're going like 20+mph) and you end up on top of it. Being able to change lanes and enter traffic from side streets/driveways with less slip is just a soooooo much better experience than not being able to do those things gracefully but in exchange for a slightly a better worst case stopping distance in fairly rare conditions (ice and fresh powder). Commuting in snow is nothing like those commercials where they drive on ice. All the traction in the world won't help you when your problem is that the tire isn't making contact with the road. Driving on ice and fresh powder are so rare it's no surprise that consumers don't optimize for that. Sure you can put snow tires on your AWD but the lions share of improvement in the conditions people actually encounter comes from AWD.

ip26 6y ago
You don't actually have to touch the pavement. Deep, aggressive, self-clearing tread seems to be enough. I put an ice spiker pro on my bike and slush goes from ice rink to no big deal, whether or not I touch pavement. I speculate most snow & slush under compression has some shear strength to offer even though there is little dry friction.
- snuxoll 6y ago
  The weight of your vehicle and heat in your tires (plus the heat generated by friction) causes slush, snow and light ice to melt. If your tires have aggressive enough treads they are just pushing the water away and making contact with the road surface. If conditions are bad enough to cause a FWD or RWD car to hydroplane then there’s nothing AWD can do to help it given the same tires. Grip is all that matters when it comes to staying put on the road, and that comes entirely from your tires on normal road cars (most road cars aerodynamic profiles generate lift rather than downforce, so you aren’t getting any aero grip unless you are driving a sports/supercar with aero elements).

Gibbon1 6y ago

AWD helps when you're under load going around a corner because the traction is distributed over four tires not just two. And AWD cars tend to have better weight balance. I've also noticed when driving AWD cars on sand and dirt they are stable at higher speeds than FWD.

snuxoll 6y ago
Traction (mechanical grip) is always distributed among four tires according to physics of center of mass, velocity and angle of travel - AWD does not change that. That said, AWD will let you put power down earlier into a corner because the extra drive wheels will help you change your angular momentum without sending you straight into a slide - but you also put extra lateral load onto your tires doing this so it's best to continue to drive like you just have RWD.
- Gibbon1 6y ago
  You're treating lateral forces and traction forces as independent variables.
  - snuxoll 6y ago
    Absolutely not, you can’t change direction without grip - angular momentum and weight are what cause lateral loads, after all. The thing is, AWD makes it easier to get going by letting you put engine torque through all four tires. The same set of tires has the same mechanical grip regardless of how many wheels are driven, so if a FWD car would spin taking a corner at X speed due to lateral load so will your AWD car (and the AWD will have an easier time doing it).
    - Gibbon1 6y ago
      Again: You're treating lateral forces and traction forces as independent variables.