2wd vs awd in snow

[Bimmerman325i]

How about an E30 with LSD, quality snows, extra weight in the back, and CHAINS? The only thing that would stop it is snow so deep that the car rides up on it and loses down force on the rear wheels.

E36 M3, quality studded (but old) snows, LSD, three 75lb sandbags, no chains, useless in snow.

Dad's E28, quality new studded tires, LSD, three 75lb sandbags, no chains, still not fantastic in snow.

Chains I don't think will make all that big of a difference, since you can't go >25mph. If you have to use them, then you need them, but for DD use outside of the Arctic Circle....not terribly practical.

[iamsam]

I agree entirely with this.

This last weekend we had a convoy going to Winter Park from Denver (~6000 feet to top of pass, ~4000ft total elevation change from WP to Denver), in whiteout conditions. I was in my awd Subaru (open diffs ftl, but 50/50 power distribution ftw) but with studded snows. Following were two rwd e30s, a 318is with LSD and studded snows, an m52 swap without either. Both E30s got stuck. I four wheel drifted the entire pass, up and down. Granted, the E30 guys were hooning a ton, as was I, but they did get stuck.

AWD is amazing in snow with proper tires, a competent driver, and elevation change. RWD is fine, but AWD frankly is better. I hate driving my E36 (also hated driving the LSD equipped E30) in snow unless it's just to go dick around in. I love driving the subaru in snow.

The difference between the winter traction and capabilities of RWD and AWD with snow tires on both is staggering. AWD has far better traction in cornering and acceleration, but not any better in braking. The added traction is very noticeable, and has saved my idiot self numerous times. I had to TRY to get my car to slide on the convoy, by trailbraking the crap out of each turn, sawing at the wheel, and flooring it in first gear. It took too much effort to lose traction. The E30s were far easier to break loose and slide, and I know Sam was enjoying it to no end. My point is that the difference in grip level is astonishing, and far in favor of the AWD.

I can't wait to put LSDs in my Scoob, thing will be insane.

me being the guy in the 318is in the above story, I must say that AWD will definitely get stuck less than RWD with all other variables held constant, but also, in contrast to what Bimmerman said, I had a blast driving my E30 up in the blizzard, and I LOVE driving my LSD 318is in the snow. The 180 degree turns up the mountain were awesome, I had my car drifting every corner all the way to the wheel locks.

However, I DID get stuck, and it wasn't a situation in which ANY car would get stuck either. I got stuck in the middle of the nice smooth hard-packed road, just because I happened to stop on a ~8% incline. Tried to get moving, and the LSD and studded snow tires just weren't enough. That is where AWD would definitely be the winner of this argument. I had to burn tire tracks through the ice and snow down to the pavement to get enough traction to get moving at 1 or 2 mph, which is enough momentum for the 318is to continue its snow ownage. And yes, I tried creeping slowly, feathering the clutch, I had two of my buddies push, jump on the trunk, etc etc, nothing worked.

Now I am not sure how an AWD car with two open diffs is much different from a RWD with LSD, both are 2-wheel drive, but an AWD car w/ two LSDs would be utterly un-stoppable, given good winter tires. Needless to say, that trip up to Winter Park made me want an iX.

[iamsam]

How about an E30 with LSD, quality snows, extra weight in the back, and CHAINS? The only thing that would stop it is snow so deep that the car rides up on it and loses down force on the rear wheels.

Yes chains would have gotten me out of that mess for sure, but as Bimmerman said, totally impractical to have installed all the time. Chains would be something that you keep in your trunk to take out in a situation like I was in, and then put back in the trunk. I like going above 25 mph.

[Bimmerman325i]

me being the guy in the 318is in the above story, I must say that AWD will definitely get stuck less than RWD with all other variables held constant, but also, I had a blast driving my E30 up in the blizzard. The 180 degree turns up the mountain were awesome, I had my car drifting every corner all the way to the wheel locks.

However, I DID get stuck, and it wasn't a situation in which ANY car would get stuck either. I got stuck in the middle of the nice smooth hard-packed road, just because I happened to stop on a ~8% incline. Tried to get moving, and the LSD and studded snow tires just weren't enough. That is where AWD would definitely be the winner of this argument. I had to burn tire tracks through the ice and snow down to the pavement to get enough traction to get moving at 1 or 2 mph, which is enough momentum for the 318is to continue its snow ownage.

Now I am not sure how an AWD car with two open diffs is much different from a RWD with LSD, both are 2-wheel drive, but an AWD car w/ two LSDs would be utterly un-stoppable, given good winter tires. Needless to say, that trip up to Winter Park made me want an iX.

Yup. Well we both know my diffs are psuedo-lockers now. Still need to figure out wtf is going on there.

[u3b3rg33k]

I'll admit that I can't find it, although quattro vs. xdrive will pull up some entertaining results (including a BMW X3 vs. Audi Q5 test done by BMW).

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.

[Gladeoffer]

Driving from Denver to Summit Co.(Breckinridge) and Eagle Co.(Vail) both ski areas in the Mnts. of Colorado 15+ times a month in a 325is lowered with an additional 70# or so in the trunk was never a worry with decent snow tires. Never found a way to get stuck in 6 years, More often than not maintaining posted speed limits on snow and ice covered roads. Hell when roads where slippery enough I would take Loveland pass just because of it's curvy ascending nature. Recent purchase of an 88ix with crap tires was just amazing, taking the same route (I-70) to my familiar destinations was stress free, easy driving. The E30's with rwd would always require a higher level of concentration on slippery roads, the ix is well F-ing easy even with crap summer tires. I aways said that awd wasn't needed and it isn't but it sure is easier. Side note E30 ix will stop on slippery surfaces better than the rwd, it's science; look it up! Not to say this applies to every awd Versus rwd vehicle but specifically to the E30 ix models with its mechanical viscus drivetrain system.

[u3b3rg33k]

I have trouble buying that an iX with crap summer tires stops better than rwd with snow tires, which is what it sounds like you're saying.

[Erik j]

I ran a iX with fuzion zr1 tires for a winter. While it sucked balls and I could not get up hills at all, it was still fun. When I put on my winter tires, I had no problems with any of those same hills.

[Cloudbase]

Man I wish I could have rallied with you guys last weekend. I happened to get stuck in my RWD LSD E30 that weekend, but it was on dry road due to a CPS that was cut in half by my A/C belt! (see sig)

Token E46xiT shot from last winter.



On the Million Dollar Highway to Silverton.

[1mz]

just in line with this thread, ill throw these out there:

http://www.ecstuning.com/Search/Snow_Socks/ES2137178/

I carry them in the trunk of my daily with Yokohama Avid H4S (not the best in snow...) and when we got hammered with snow this past week they proved their usefulness beyond belief.

r3v disclaimer- I am NOT saying that these are a suitable substitution for snow tires or awd or anything else - however, as a contingency plan to get you home (especially if you live off of some pretty steep roads as I do) then they are well worth the $100.

Hell I'll carry a set of these in my trunk until I die after this week just incase, and as far as durability is concerned - theyll last at LEAST one winter and at $100, I wouldn't have an issue getting another set for next year if needed.

[nando]

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.

the earlier E46 AWD is an open core, the Xdrive system is an electronically controlled wet clutch

an ix would easily go up that ramp like the xdrive system. I'm surprised at the audi, I wonder if it was one of their automatic models?

[u3b3rg33k]

the earlier E46 AWD is an open core, the Xdrive system is an electronically controlled wet clutch

an ix would easily go up that ramp like the xdrive system. I'm surprised at the audi, I wonder if it was one of their automatic models?

I believe that is true of the center diff, however I am under the impression that the current axle diffs are still brake limited slip only, due to the aftermarket upgrade options.

[nando]

yes, but it's still a huge improvement over the E46, where even the center diff was open.

[regnu]

'79 Camero Z28.. sketcky in snow but with weight in the trunk and good tires would still go in CT winters and never got me stuck on my trips to Powder Bump when it was snowing.

'89 civic Studed snow tires up front and snows out back would get me from Burlington to Stowe no problems so I could ride 3 ft of fresh pow.

'87 4000 cs Q with snows.. I seriously think I could have berried the car in a snow bank and it would have made it out.. most fun car I ever have driven in the snow.

'91 90 20v Q good but not as fun as 4000 moved from VT to GA and it wasn't a fun car at all anymore

'89 325is.. i live in GA now.. screw risking it, if it snows down here I use the wife's 2000 4Runner SR5 4x4.

as stated before tires tires tires.

[Gladeoffer]

I have trouble buying that an iX with crap summer tires stops better than rwd with snow tires, which is what it sounds like you're saying.

Yea sorry, let me clarify. Given a rwd with summers and a ix with same tires the ix does stop shorter(an observation, nonscientific experiment totally subjective on my part). I would logically say the same with snows on both. I base this on driving the rwd in similar conditions and just as shitty summers. same tread and depth.not sure about temp specs though, as my currant ix. Information I had recently read(thought it was kind of BS. myself), may have been somewhere in the ix specific bimmer forums from an old magazine comparison. Hope thats more betterer.