2wd vs awd in snow

[Bimmerman325i]

The better braking would be due to more mass over the front axle/front half of the car. More driven wheels with equal tires and brakes does NOT change braking performance, but added/redistributed mass does.

[u3b3rg33k]

I'm not quite sure how that works, unless the AWD system increases rear bias and that happens to be advantageous. The iX is a heavier car, and given the same tires on the same road, I would expect the lower mass car to stop faster, all other conditions equal.

[Bimmerman325i]

^ the added mass on the front wheels gives better front end braking, but not all that much. Overall though, yes, the heavier car will stop slower than a lighter car.

[Gladeoffer]

From what I understand the VC and ABS system in the ECU have something to do with it all. Just my 2 cents.

[Vtec?lol]

Also, subarus don't have that great an AWD system. A lot of them are double open diffed with no traction control. In really nasty circumstances, they are basically 2WD.

Can someone tell me wtf the point is in owning an awd car with open diffs? wouldn't that mean if one tire loses traction the car loses power to the road?

[Mike]

325e w/lsd > 325i w/lsd

[u3b3rg33k]

From what I understand the VC and ABS system in the ECU have something to do with it all. Just my 2 cents.

IIRC, the iX ABS system is designed to handle the AWD system, so it doesn't freak out.

Can someone tell me wtf the point is in owning an awd car with open diffs? wouldn't that mean if one tire loses traction the car loses power to the road?

That's like asking wtf the point is in owning an open diff 2wd car. Lots of people do that...
but for the real answer:
I don't think they're set up that way. It really depends on the diffs and t-case setup. Eg, our explorer is open F/R, t-case center, so there is only a problem left to right, not front to back.

[nrubenstein]

All that electronic nonsense does serve a purpose, but the bmws would still benefit from a non-open core. I've test driven the 335d, and 335xi in the winter, and it's very obvious when the system is operating. As I understand it, a torsen will complement traction control nicely, amplifying the efforts of the system to move power around.

I'm not in any way stating that I don't like having the mechanical stuff. I'm just stating that in non-performance situations, the electronic half-assery works a lot better than you'd expect.

[Bimmerman325i]

Can someone tell me wtf the point is in owning an awd car with open diffs? wouldn't that mean if one tire loses traction the car loses power to the road?

That's like asking wtf the point is in owning an open diff 2wd car. Lots of people do that...
but for the real answer:
I don't think they're set up that way. It really depends on the diffs and t-case setup. Eg, our explorer is open F/R, t-case center, so there is only a problem left to right, not front to back.

Same for my Subaru. It's a manual trans car, so it has transfer clutches in the center diff (aka, LSD center) to apportion the power front/rear/ The open diffs only matter side to side. It's not optimal, but it works incredibly well.

[u3b3rg33k]

Here's proof, AWD + mash gas > 2WD + mash gas



Because when I want to go somewhere in the rain, I drop the clutch and mash the gas.

[u3b3rg33k]

Honestly, the SH-AWD seems like one of the best systems out there.
I think it's basically the same system that is in the new S4, and in the bmw active M diff. Honda's real-time AWD is one of the most useless systems.


What people often don't realize, is the audi quattro or hummer (torsen) system works great for these tests, IF you step on the brake as well, as that provides torque for the torsen's to bias against. I don't consider that cheating any more than I consider electronics cheating (depending on the day, my answer might change).

[SpoolnDaapex]

Do any of you disable ABS in the winter?

I did for the first time this winter and its much better on surfaces that have just been snowed on. The tires bite right through the snow and grab the pavement. Doesnt do much on ice covered roads though.

[u3b3rg33k]

My abs works exactly the way I think it should in snow.

[Bimmerman325i]

Here's proof, AWD + mash gas > 2WD + mash gas



Because when I want to go somewhere in the rain, I drop the clutch and mash the gas.

That's my gen of Legacy. Awesome car.

[kid325e]

My iX is better than any RWD car i've ever driven in the snow. Period.