FWD/RWD/AWD: Which vehicle safest in snow/ice?

Battening down here in Jersey for Jonas!

I read a recent thread here about the advantages and disadvantages of front- and rear-wheel drive. Though I’m def. not intending to go jaunt around during this storm, I’m curious about opinions on which of our vehicles would be safest on snowy/slick roads.

Car one > Jeep Wrangler, front- and four-wheel drive. I’ve driven it in light snow a few times, my brother says that it’s too light to be a really safe winter ride.

Car two > Jeep Grand Cherokee Laredo, FWD, four-wheel drive conked out last week and I received a recall notice today from Chrysler to fix the system. I obviously won’t be getting it fixed this weekend :). It’s a big, heavy V-8 I’ve driven in past winters. I’ve slid a few times, but nothing really scary.

Car three > BMW sedan, RWD. It’s fairly new to me and I’ve never driven it in winter conditions. It has Dynamic Stability Control, no idea if that is any advantage.

The car with the best tires.

Otherwise, the Laredo.

The safest vehicle on snow and ice is the one with a driver that is cautious and aware of conditions. There is no drive system or traction control that will prevent a driver from exceeding the conditions and losing traction, in which case the law of conservation of momentum takes over.

That being said, out of the list of vehicles in the o.p. I would select the Cherokee first with the Grand Cherokee a nudge behind. Both have pretty decent IIHS ratings, and while four wheel drive is not a panacea it may be useful if you get in a really slick parking lot or unplowed drive. Weight is not really a concern unless you plan on driving through heavy drifts of snow, and the power of a V8 engine is just asking for trouble. The US National Ski Patrol has used four cylinder Subaru 4WD and AWD vehicles as its official car (meaning it is recommended and made available to members for a discount) for twenty-odd years. You need control authority and confidence with how the vehicle handles in slick conditions than you do power.

I would not take the BMW out in snow or heavy inclement weather of any kind. Rear wheel drive BMWs have excellent handling characteristics on dry pavement but are not good winter driving cars. Dynamic Steering Control is BMWs label for their electronic stability system. It does provide some benefit to traction and steering control on slippage by controlling the throttle and selectively applying ABS brakes, but there is only so much that it can do. The car will also be a far more expensive repair if you end up running the car into a lamp post or a curb. Leave the BMW in the garage and take the Cherokee.

Be save, and when in doubt, slow down or stay home.

Stranger

Not true. I drove Jeep Wranglers for five years in Anchorage winters without incident. As someone else mentioned, it’s not the vehicle so much as the driver. Now, that’s not to say that if I’d ever had to jump on the brakes that the Jeep wouldn’t have swapped ends on me. Stranger pretty much nailed it.

Rear wheel drive is by far the worst. When your drive wheels and your steering wheels are different there are some conditions where you have no control no matter how slow you go. Of course conditions that bad are very rare.

I didn’t see an all wheel drive on your list. 4WD and AWD are really different animals. AWD cars with snow tires are the ticket for snow. I saw a video once by some Canadian department of somethingOrTheOther showing stopping, turning, etc. by cars with and without AWS and snow tires. AWD and snow tires won by a large margin.

I agree though. Park the BMW. At least the Jeep has some weight to it and that will keep you safer in a mishap.

If those conditions are so very rare, then how in the name of common sense can RWD be “by far” the worst???

Quite frankly, as far as the safest goes–which is what the OP was asking–RWD is probably the best. As I pointed out in the other thread, for some skids, all you have to do is tap the gas, and the car straightens right out.

You asked which car is safest in snow and ice. The Grand Cherokee and then the BMW. Wranglers are some of the least safe cars on the road.
But I’m not sure safest is what you meant. 4WD, and to a lesser extent, AWD help you go. (They don’t help you stop). If I was going out in a storm and I had your choices, I would take the Wrangler with working 4WD. That car is most likely to get you where you are going.

The conditions where you have no control at all are very rare. But it most every snow/ice condition you have less control than you would with the other options.

Bought a Honda CR-V for my wife several years ago. AWD was the most common version, but we chose FWD to save $1500, gain +1 on highway MPG, and get increased reliability (hey, fewer parts to break, right?). Instead, I plowed that $1500 into snow tires/rims. I have no doubt that this car stops, goes, and turns better than the AWD version would have with all-season tires.

I think AWD/4WD can give drivers a false sense of confidence: they accelerate better than FWD/RWD cars (assuming all are on the same type of tire), but they don’t stop any faster, since every car has all-wheel braking.

I have a RWD car. With snow tires it does fine in the winter. Electronic Stability Control (that’s what BMW is calling “Dynamic Stability Control”) isn’t really an issue; I tend to turn it off when I start the car because I enjoy managing traction myself. For someone who doesn’t know how to steer a car out of a skid, ESC can be helpful, but like AWD/4WD, it can foster overconfidence; it doesn’t increase traction, it just keeps the car pointed in the direction it’s moving, so you won’t be sideways when you hit slide off the road and hit the tree.

Telemark nailed it in 1. Summer and “3 season” tires become rock hard in cold weather, and therefore provide a very small contact patch. The change to snow tires isn’t so much about the tread pattern or any studding, but in the temperature range of the rubber compound.

All-season tires will vary greatly in this regard. I’m going to guess the BMW doesn’t have appropriate tires, between the two Jeeps in comes down to what’s wrapped around the wheels.

Thanks, this is all really interesting to me!

Not intending, unless one of us accidentally cuts a finger off and needs to go to the ER, to budge from home through Sunday. I grew up in “Idaho snow” and learned to drive in really deep snow in a variety of mostly craptacular '70s vehicles.

I trust myself to be slow and cautious in bad conditions, but don’t trust other NJ drivers who tend to be crappy drivers in snow.

[QUOTE=Electronic Stability Control (that’s what BMW is calling “Dynamic Stability Control”) isn’t really an issue; I tend to turn it off when I start the car because I enjoy managing traction myself. For someone who doesn’t know how to steer a car out of a skid, ESC can be helpful, but like AWD/4WD, it can foster overconfidence; it doesn’t increase traction, it just keeps the car pointed in the direction it’s moving, so you won’t be sideways when you hit slide off the road and hit the tree.[/QUOTE]

Is it true that turning off the DSC enables better acceleration? I’ve seen it debated on BMW dorkboards.

Depends on the driver. For the 99%, leave the ESC on, for the <insert amazing driver of your choice here>, turn it off and have at it.

As to this gem from flyer:
<snip> Quite frankly, as far as the safest goes–which is what the OP was asking–RWD is probably the best. As I pointed out in the other thread, for some skids, all you have to do is tap the gas, and the car straightens right out. <snip>

only applies comparing FWD and RWD. with 4WD/AWD it responds pretty much the same as RWD; tap the gas and the rear swings into line. I’ve been driving winter roads 32 years and I have a Subaru on winter tires, take what you will from that.

tldr: Telemark nailed it.

Jeep Wranglers are rear-wheel drive when the four-wheel drive is not engaged.

I’ve been driving Jeep Wranglers since 1994, and wouldn’t want to be driving anything else (snow or no snow). They handle extremely well, have high ground clearance (an absolute necessity when driving in any serious snow) and being relatively light helps. They are rear wheel drive, as noted, without 4WD engaged. I’ve had a lot of cars, and can tell you from direct experience that nothing I’ve driven handles better in the snow.

We’ve also had a series of Hondas (three Accord Sedans & one Odysee Minivan), which have all performed admirably in the snow, but are really no match for the Jeep. The Hondas all had front wheel drive.

Front wheel drive cars tend to handle well in the snow because the weight of the engine is directly above the drive wheels, proving needed weight for traction.

Quoted for truth. Ignore the rest of my post, and follow what Telemark has said. Seriously.

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Hey Jenn, consider selecting which vehicle to use for a winter storm driving in the following priority, eliminating vehicles as time as you go down through the list:

  1. True snow tires. If only one of your vehicles has true snow tires, that is the one to drive if there is snow or ice.

True snow tires will give you far greater control when turning, let you come to a stop far earlier, and significantly reduce slipping and sliding. Here’s a vid: https://youtu.be/elP_34ltdWI . All-season/four-season tires are really only three season tires and are not true snow tires, so if that is all any of your vehicles have, try not to drive if there is ice or hard-pack snow on the road. Summer tires are truly dangerous for driving on snow or ice. If you are in the market for snow tires, the narrower the tire the better, for fat tires tend to float more than narrow tires. If you are driving in mud, go with fat tires to float you rather than bury you in the mud. If you are driving in snow, go with skinny tires that dig down through the snow to give you traction on the road.
2. Anti-lock braking system (ABS) brakes combined with Electronic Stability Program (ESP)/Dynamic Stability Control (DSC)/Electronic Stability Control (ESC).

ABS keeps the wheels from locking up and skidding when you brake by applying and releasing the brakes very rapidly. Various manufacturer’s stability programs work with the ABS brakes to automatically apply brakes to one or more of the wheels if you start to skid out, which if successful will permit you to retain control of the vehicle. The stability programs are pretty nifty, and can save your bacon if you are momentarily inattentive at the wrong time, or if you simply misestimate in a turn. Here’s a vid: https://youtu.be/C4-Lbt8KHkw . Your BMW and Cherokee have ABS and stability control. Your Wrangler probably has these if it is a JK series (2007 or newer). To check to see if your Wrangler has ESP, look at the row of buttons/switches below the temperature control dial on the dash. The button/switch on the right of the row normally will not say anything. Start the Wrangler, let it run for a few seconds, and then press this far right switch once. If it lights up and says ESP OFF, it means that your Wrangler is equipped with ESP, and you just turned it off, so press it again to turn it on. The default is ON, so the next time you start the Wrangler it will be on automatically. If it has ESP, then it has ABS. If it does not have ESP, watch the lights on your instrument panel when you partially turn you key bust before starting the Wrangler and see if one of them says ABS. If none say ABS, then you do not have ABS. I started out without power brakes, let alone ABS, but despite knowing how to drive old tech in the winter, today I would not drive on ice or hard-packed snow without ABS, and I would try to avoid driving on ice hard-packed snow without ESP/DSC/ESC.
3. General crash worthiness.

Look up each of your vehicles on the Insurance Institute for Highway Safety’s Highway Loss Data Institute’s webstite for their crass worthiness ratings. Here’s the link. http://www.iihs.org/iihs/ratings My guess is that of your three vehicles, the Wrangler would be kicked off the island on this one, for its chassis and body are old-school.
4. For urban and highway snow or ice, all wheel drive rather than four wheel drive rather than front wheel drive rather than rear wheel drive.

Both all wheel drive and four wheel drive apply power to all four wheels, which helps when the road surface is not consistent, such as when there is snow or ice on the road. Here’s a vid on the basic difference between most all wheel drives and most four wheel drives: https://youtu.be/f_G7XS213f8 .

With typical all wheel drive, power is coordinated between all four wheels, and with the better types of all wheel drive, power vectoring constantly adjusts the power to each individual wheel to ensure you get maximum traction. For good gas mileage, all wheel drive sends most or all of the power to the front wheels most of the time unless assistance is needed for traction is also needed from the back wheels. Unfortunately, most all wheel drive vehicles do not have a crawl gear.

With typical four wheel drive, the back two wheel are coordinated with each other and the front two wheels are coordinated with each other, but the back wheels and the front wheels front wheels are only crudely coordinated with each other, with the power between the front and back sets of wheels being somewhat equally split rather than automatically varied depending on traction needs. The good thing about four wheel drive is that it usually includes a crawl gear, so that you can effectively use your engine’s power to crawl up or through obstacles that otherwise would stop you, but although four wheel drive wins the brute force committee award for off-road driving, it does not offer the subtle automatic traction control that all wheel drive does.

Pity that the Cherokee’s all wheel drive is not working. Although I am not certain, it sounds like you might have a Jeep’s version (Quadra Trac II) of an all wheel drive that can transfer full power to either front or rear axle and which also has a crawl gear – the best of both all wheel drive and four wheel drive worlds. Since it is busted that leaves you with front wheel drive only, for although the Wrangler’s four wheel drive would win the Brute Force Committee Award for crawling up steep hills or over obstacles in the bush, or for snow-wheeling (driving on forest roads that have snow almost up to the floor of the vehicle), or for being really good at getting unstuck, it’s already out of the competition for city and highway driving based on crash worthiness.

Front wheel drive puts much more of the weight of the motor and transmission over the drive wheels than rear wheel drive does. The more weight on the wheels, the greater the traction. The Bimmer would lose to the Grand Cherokee on this.
5. Weight.

When driving on snow, the heavier the better, because you will not be bounced around as much in the snow and slush ruts, and thereby are less at risk of spinning out, but don’t let this lull you into driving too fast, for the heavier the vehicle, the longer it takes to stop it in a slide. Here too, the Bimmer would lose to the Grand Cherokee.
6. Ability to see the road clearly.

It helps a lot if your vision is not impaired by the salt and slush being thrown up by other vehicles on the road. The BMW loses again, simply because the driver sits closer to the road (a good thing for vehicle stability, but a bad thing for seeing what you are driving through).
6. Conclusion.

By process of elimination in an effort to avoid being eliminated on the road, I’d go for whatever has true snow tires, and if none had them, I’d have a stay-cation at home until the roads are bare and dry, at which time my first excursion would be to a tire store for snow tires (Nokian Hakkapeliitta factory studded, else Nokian Hakkapeliitta non-studded, else Bridgestone Blizzak non-studded).

Assuming snow tires, my preference for safe urban and highway winter driving would be the Jeep Grand Cherokee, then the BMW, then the Jeep Wrangler.
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Winston Smith, I hear what you are saying about the Wrangler, but I respectfully disagree, for I find its lightness results in it bouncing around a bit when the highway has a few inches of tracked snow or when it has iced over hardpack that has been chunked by plows. More weight would help. Offroad? Wrangler without hesitation, but for a highway, the heavier Grand Cherokee.

I say this as a Wrangler Unlimited owner who regularly makes long winter drives on highways and forest roads, and who has the back of it set up for sleeping when the roads are closed. It is thoroughly competent in the worst of winter storms (e.g. semis stopped on the roadway of the Trans-Canada highway in one hell of a blizzard, but the Wrangler just kept on crawling past them to the next town). As you know, Wranglers only have to stop if snow is so deep that it causes the frame to float, and for getting stupid in the bush, the fun factor is off the scale, so I hear what you are saying.

Now that made me laugh, simply because it is in a thread on preparing to drive in a winter storm. :wink:

Good one, Muffin! :wink:

At this point we would need equipment and doggies from the Iditarod superstore to go anywhere. For some reason our border collies and labs refuse to drag the sled.

19" and counting in our little outpost in Jersey.

Muffin, I concede the point because I’m biased, and because I’ve never driven a Grand Cherokee. BTW, great post.