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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

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).
  - throwaway0a5e 6y ago
    >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. How can anyone say this with a straight face? Spreading the motive power out over twice as many tires does a ton to help.
    - snuxoll 6y ago
      Hydroplaning means you have a layer of water between your tires and the road surface. Regardless of whether you have two driven wheels or four, if they aren't making contact with the road you aren't putting any power down and your wheels are just spinning. The only thing that can help you is better tires that can move more water out from under them, hopefully giving you a contact patch with the surface.
      - throwaway0a5e 6y ago
        Imagine you're driving highway speed and crossing some slush to change lanes. As you drive through that slush would your rather be trying to put all the vehicle's motive power through two tires or four? Do you dispute that doubling the number of tires moving the vehicle forward will drastically reduce the ease with which the vehicle breaks traction crossing over the slush?
        snuxoll 6y ago
        > Do you dispute that doubling the number of tires moving the vehicle forward will drastically reduce the ease with which the vehicle breaks traction crossing over the slush? Grip and traction are two words for the same thing, the only thing that determines grip are the tires plus the weight (and distribution thereof) they are carrying. So, yes, having AWD does nothing to help grip - that's a mechanical force between your tires and the road. AWD helps utilize grip, by distributing torque to all four wheels. It helps acceleration by avoiding wheelspin where two driven wheels don't have the grip, but nothing else. Edit: Clearance is more important when trying to cross over piles of shit on the road anyway. It doesn’t matter how many wheels are driven on your car if you bottom out.

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).
- throwaway0a5e 6y ago
  >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. How can anyone say this with a straight face? Spreading the motive power out over twice as many tires does a ton to help.
  - snuxoll 6y ago
    Hydroplaning means you have a layer of water between your tires and the road surface. Regardless of whether you have two driven wheels or four, if they aren't making contact with the road you aren't putting any power down and your wheels are just spinning. The only thing that can help you is better tires that can move more water out from under them, hopefully giving you a contact patch with the surface.
    - throwaway0a5e 6y ago
      Imagine you're driving highway speed and crossing some slush to change lanes. As you drive through that slush would your rather be trying to put all the vehicle's motive power through two tires or four? Do you dispute that doubling the number of tires moving the vehicle forward will drastically reduce the ease with which the vehicle breaks traction crossing over the slush?
      - snuxoll 6y ago
        > Do you dispute that doubling the number of tires moving the vehicle forward will drastically reduce the ease with which the vehicle breaks traction crossing over the slush? Grip and traction are two words for the same thing, the only thing that determines grip are the tires plus the weight (and distribution thereof) they are carrying. So, yes, having AWD does nothing to help grip - that's a mechanical force between your tires and the road. AWD helps utilize grip, by distributing torque to all four wheels. It helps acceleration by avoiding wheelspin where two driven wheels don't have the grip, but nothing else. Edit: Clearance is more important when trying to cross over piles of shit on the road anyway. It doesn’t matter how many wheels are driven on your car if you bottom out.