Winter drivinng: FWD and RWD with snow tires vs. AWD with all-season tires - what people who have done the tests say

All things being equal 4WD will be better than FWD will be better than RWD and snow tyres will do better than regular road tyres. IMHO essential for any winter driving is ABS, and if you do have a RWD BMW get one with snow mode on the gearbox.

IME ABS doesn't help when driving on snow or in very slippery conditions.

and if you do have a RWD BMW

My BMW has a snow setting, but I haven't had a chance to try it out yet, but theoretically it should be better with it than without. Mike.

What is "snow mode"? Some kind of automatic tranny thing where the car starts in 2nd gear? I just have traction control on our LS400 and never have any trouble (with snow tires mounted).

I find that the combination of snow tires and traction control on a RWD car (unless it is ridiculously nose heavy, like say an original Hemi-Cuda) results in no worries in any amount of snow that your car can go over and not turn into a plow.

- GRL

R. Mark Clayt> > It seems like every year someone posts a message asking about how to make

Yep.

Yep.

Use the right tool for the job.

Mark, Mark, Mark... we've been through this before.

All things are *never* equal, and that is the real point here.

For one thing, when was the last time you saw a 4WD or AWD vehicle equipped with *real* winter tires? Where I live (Northern New England) people with 4WD or AWD just fit them with all-season tires year round. Why? beats me... but that is exactly what they do. Maybe they figure (like you) that because the AWD provides superior acceleration in the snow they will not need them. Well, as GRL's evidence supports, they are just wrong. Dead wrong. Stupidly dead wrong.

Case in point: It happens to be snowing like gangbusters here today.

10"+ of fresh. The plows (being a Sunday) are not making too much effort to get things cleared up and not too many people are heading out. Probably mostly due to the news reports, stirring up paranoia, etc. Well I needed to get to the pharmacy, so passing up the AWD SUV (It is my boat hauling machine) equipped with all-season tires and I jumped into my E36 325i with the Michelin Arctic Alpins mounted. Needless to say it went through the snow with NO problem whatsoever and I got the required meds. And yes, I feel much better now ;-)

Of course, on the way I passed some fool in the ditch on the side of the road being assisted by the local cops and winched out by a tow truck. Oh yeah... it was one of those cute 4WD mini-SUVs. Want to guess what kind of tires it had on it?

So that is the point that GRL is making, and the same one I have made numerous times before. A RWD BMW with Snow tires is better than ANY other vehicle (FWD, AWD, 4WD, or obviously RWD) with "all-season" tires on it.

My experience is contrary to your. In emergency stopping situations the ABS works well in snow or slippery conditions. It can be disconcerting until you get used to how it works, but it does allow the maximum available braking while still maintaining steerage.

Yeah mine does too. It's called 3rd gear (it's a manual trans) ;-)

3rd gear actually.

I prefer to turn traction control off sometimes and use the gas pedal to steer the car at times. Much more fun...

The only conditions where ABS iis counter-indicative is deep fresh snow (rare) or pebbles.

From first hand practical experience it is, although an experienced driver with a a manual box wuold do quite well by comparison. OTOH even a top rank rally driver would be likely to better anything but a novice with ABS on wet / icy roads.

I live in England UK, and fortuitously it snows not a lot.

1963 when I lived in Scotland we had maybe -25C & 15cm snow ... worst winter in my lifetime (in UK), but OTOH no 4WD BMW's then.

Maybe us Brits should duck out of discussions of winter driving in the colonies...

Well, in my admittedly limited experience with an '02 manual gearbox IS300, when they tell you that the standard 17" performance tires should not be used in virtually any kind of snow at all, you ought to believe them. I've gotten that car stuck in 4 inches of snow, with clear road less than 3 feet away, and I couldn't even get the car to move 3 feet until I just got out and shoveled the 3 feet of snow. At one point I ran 4 dedicated winter tires on it (Blizzak LM22 on 16" rims), and using the snow settings, turning off traction control, and working the manual gearbox, I could barely make it through 5 inches of snow.

I finally gave up, and just kept the performance tires on the IS year-round. I bought a used 2-door RAV4 with a manual gearbox and locking center differential, put 4 big-ass snow tires on it, and only drive it in the snow and when I need to haul dirty cargo, and maybe once a week just to keep a charge on the battery. I think I put around 1,000 miles a year on that car, but it's very handy on days like today. I can easily bulldoze through plowed-up walls of snow that are 3 feet high and 6 feet wide.

"GRL" wrote

Is it the issue that's currently on the stands? I looked through it but didn't see it. Not sure which issue it was, but it said "to be displayed on the stands until March 21."

Pete

perhaps so... less than 6 inches is a "dusting" by our standards in the Northeast. OTOH, it's enough to cripple some of our more southern cities (where incidentally they do not believe in winter tires)

conditions.

The problem with ABS in snow or icy conditions, with varying levels of grip, is that it does not allow different braking techniques to be used in line with how much grip there is at any particular moment. At times it may be better to lock the wheels to slow down or stop At other times, it might be better to cadence brake. Varying the rate to give the best result. IMO and experience, basic ABS is not sensitive enough in very slippery conditions. It doesn't give any feel to the brakes. They're either on or off, with virtually nothing in between. I'm not against ABS per se. It's made a good contribution to road safety. I just wish sometimes that I was able to switch it on and off as required in the winter months, without pulling the fuse. Mike.

It seems to me, and from my experience, the ABS is actually able to react to the varying traction conditions much faster under these conditions than even the most adept human driver. In dry road conditions I think that your analysis may be correct...

It is never better to lock up your brakes on any surface except, maybe, loose gravel where a plow effect can come into play. Lock 'em up on any hard surface and you will increase your braking distance and also loose steering control. A very good driver on the right surface may be able to beat an ABS car's stopping distance by constantly holding the tires on the verge of lock up. But there are few such talented people around.

- grl

And a FWD car with snow tires is better than a RWD with snows, and an AWD or 4wd with snows is better still.

One thing to add and reinforce. The driver is the key factor that makes or brakes that 30% advantage. Case in point when I was a teenage need for speed type I had a sweet '82 Trans-Am that I thought snow tires would help on. On Super Bowl Sunday 1996 I got it stuck 6 times the same day!!! After that I would tell people my Trans-Am would get stuck on an ice-cube. Of course years later when I got older I realized you don't have to slam the gas and redline during every takeoff in the snow. So no matter how good you think tires are and you may think tires are the reason person X with Y tires and X wheel drive is stuck, their is a very good chance driving skill has a lot to do with it. Doh!

You should try it with good tires sometime. I used to think ABS was a joke, until I ditched the all-seasons...