AWD Vs FWD Living Through Snowy Winters?

[Mr._Graybeard]

+1

Had 'on demand' 4WD back on the mainland for a while. It would get you into trouble a lot faster than the brakes would get you out of it.

Spent most of my years in snow country and I found that having a vehicle with either manual transmission or an automatic which could be placed in 2nd gear made a big difference in getting out of slippery snow (and even ice). Using 2nd gear manual or auto lowers the torque available so that non-limited slip differential vehicles won't spin one tire (the one without the traction.) YMMV

While I was w*rking I had an 85-mile round trip commute in Wisconsin. Any time we had a pretty good snow, the majority of vehicles I'd see in the ditch were SUVs. I assume that most were AWD.

One of the keys to driving in low-traction conditions, IMO, is to avoid coasting. Do not lift your foot off the throttle abruptly. If you want to slow down, brake. Your front wheels may lock up, but you'll continue in a straight line.

One of the great advantages of front-wheel drive: if the vehicle starts to fishtail, you can straighten it out by accelerating. It's counterintuitive, but it works.

 

[RetiredGypsy]

Growing up among a family that loved to get out in the mountains, I had the advantage of learning that 4WD (and I'll assume AWD in the same conditions) meant not that you could drive fast, but you should drive slow. Like, incredibly slow. 4-5 MPH was a pretty good clip through bad mountain/desert terrain.

 

[moneyviking]

FWD is fine, but definitely get snow tires, they truly make a difference. As a test I drove the same car on the same road conditions on the way to the tire shop and on the way back home, night and day different.

 

[MRG]

Many great posts. I've seen a few talking about ice and the difficulties of stopping.

I haven't seen any posts about chains. If you really need to get somewhere and there's bad weather and limited traction chains can be your friend. Not much fun to install, not too smooth of a ride, but chains allow for traction. Two wheel drive or whatever, unless you twist a driveshaft, chains will give you traction.

 

[RetiredGypsy]

Many great posts. I've seen a few talking about ice and the difficulties of stopping.

I haven't seen any posts about chains. If you really need to get somewhere and there's bad weather and limited traction chains can be your friend. Not much fun to install, not too smooth of a ride, but chains allow for traction. Two wheel drive or whatever, unless you twist a driveshaft, chains will give you traction.

At some point entering Colorado through the mountains, the cops were out stopping people with a mandatory instruction to install tire chains to go any further. As a little kit getting to help my dad install them, it was a really cool experience. Like a positive version of A Christmas Story without the profanity and soap.

 

[brewer12345]

Many great posts. I've seen a few talking about ice and the difficulties of stopping.

I haven't seen any posts about chains. If you really need to get somewhere and there's bad weather and limited traction chains can be your friend. Not much fun to install, not too smooth of a ride, but chains allow for traction. Two wheel drive or whatever, unless you twist a driveshaft, chains will give you traction.

Ah, if it gets that bad I stay off the road.

 

[Bamaman]

As a Tennessee native, I can tell you we're lucky to get one or two snows per year, and they just last a couple of days.

I've had front wheel drive vehicles up to the bumper in snow and still didn't get stuck. If you were moving to Chicago or Minnesota, I'd tell you to get AWD.

But for Tennessee's climate, front wheel drive with regular OEM tires is sufficient.

I can tell that many people are passionate about their transportation. As someone that lives 11 miles from Tennessee and has spent my whole life there, we very seldom even see snow in the Mid South.

We're more in an ice belt. You can have the biggest 4x4 pickup truck with the biggest mud tires and you're going nowhere on ice.

Save your money and just go with a front wheel drive vehicle and you can navigate any weather that East Tennessee's going to dole out.

Heck, this winter, it's been 70 degrees most days. I've only worn a coat maybe 3-4 times. I cannot remember driving in snow in years around here.

 

[travelover]

.........definitely get snow tires,..........

......... If you really need to get somewhere and there's bad weather and limited traction chains can be your friend...........

OP is going to live in Tennessee. I've lived in Michigan all my life and have never owned snow tires, never owned chains and have driven a 2 wheel drive vehicles most of my life. Even AWD is probably overkill in Tennessee.

 

[6miths]

In Ontario we only drive AWD with snow tires. Need this for the "cottage" road. What is not having an accident or ending up in the ditch worth to you? Worth a lot to me.

I think this 'we' doesn't mean 'the people of Ontario'. 99% (ok I made that up) of the people of Ontario don't have AWD vehicles. As mentioned AWD can make you go faster in slippery conditions but not stop faster... As pointed out snow tires if one lives in a snowy area. In much of Southern Ontario, where most to the population is, snowfall is not that frequent, and roads are cleared quickly many go without snows. A survey done recently said that snow tire use in Ontario had gone from 35% to 65% between 1998 and 2014. Two of our vehicles have snows on metal rims and the other has all-weather Michelins with a softer rubber compound for colder weather. One of the reasons for snows is that we have four young drivers in the family. Driving to conditions is not their forte.

I would have thought that unless one was actually in the mountains Tennessee that snow tires wouldn't be necessary and then only if you actually were forced to drive in bad conditions. One of the benefits of being retired is I can just go tomorrow or the next day.

 

[pb4uski]

....One of the keys to driving in low-traction conditions, IMO, is to avoid coasting. Do not lift your foot off the throttle abruptly. If you want to slow down, brake. Your front wheels may lock up, but you'll continue in a straight line. ...

Bad advice in my experience.... lifting off the throttle allows the wheels to gain traction, not lose traction... and braking increases the risk of losing steering control entirely (albeit less so with today's ABS systems).

In over 40 years of winter driving in Vermont and Massachusetts I can't ever recall losing control when lifting off the throttle.

 

[Music Lover]

While I was w*rking I had an 85-mile round trip commute in Wisconsin. Any time we had a pretty good snow, the majority of vehicles I'd see in the ditch were SUVs. I assume that most were AWD.

Buying a vehicle with AWD doesn't make someone a better driver.

Around here, the vehicles I see in the ditch in winter usually have all-season tires on instead of winter tires.

 

[GrayHare]

Re: Snow tires and rims: You have to ask yourself if you are really going to want to store a set of these somewhere all year round, make an appointment at the shop, load them into the car, have the work done (and pay for it), then unload the tires that were on the car and store them.

My dad did that, and I don't mean taking the car and tires to the shop. For frugality he did not have an extra set of rims. Instead cheap labor (me) was assigned the task of taking each tire off the rim and putting the other one on. I'd rather recycle dryer sheets.

 

[Mr._Graybeard]

Bad advice in my experience.... lifting off the throttle allows the wheels to gain traction, not lose traction... and braking increases the risk of losing steering control entirely (albeit less so with today's ABS systems).

In over 40 years of winter driving in Vermont and Massachusetts I can't ever recall losing control when lifting off the throttle.

https://en.wikipedia.org/wiki/Lift-off_oversteer

I had this happen in March 1995 while driving a FWD Ford Probe (I remember the date because my uncle was dying in a hospital ICU, and I was in a rush to be there). There was a layer of slushy snow on the road, and I had just crested a hill, headed onto a downhill slope. I backed off the throttle, and as I descended down the grade the car began fishtailing. Ultimately it rotated 270 degrees and came to a stop in the center median. Fortunately I didn't hit any guardrails or slide into the oncoming lanes.

A couple years later I took a two-day driving course at the Bridgestone Winter Driving School in Steamboat Springs, Colo. That's where I learned the physics of what had happened to my car a couple years earlier, and how to avoid it.

When you back off the throttle, the momentum of the car shifts its center of gravity forward, toward the front wheels. That reduces the G forces on the rear wheels. If the road surface is greasy enough and/or the road grade enhances the weight shift, the rear wheels can break loose. Since the front wheels are maintaining their grip, the car becomes prone to oversteer.

When you apply the brakes to slow under those conditions, it balances out the car by reducing effective traction up front -- it performance driving parlance, it "settles" the car.

 

[samclem]

My dad did that, and I don't mean taking the car and tires to the shop. For frugality he did not have an extra set of rims. Instead cheap labor (me) was assigned the task of taking each tire off the rim and putting the other one on. I'd rather recycle dryer sheets.

I'd bet the % of people in the US population who have actually mounted a car tire on a rim using only hand tools is very, very small. It's work, and quite easy to punch/pinch a hole in the inner tube (remember those?) while doing it.
Your dad made you a better person.

 

[travelover]

Bad advice in my experience.... lifting off the throttle allows the wheels to gain traction, not lose traction... and braking increases the risk of losing steering control entirely (albeit less so with today's ABS systems).

In over 40 years of winter driving in Vermont and Massachusetts I can't ever recall losing control when lifting off the throttle.

Maybe the distinction is the difference between going into a coast with no deceleration and an abrupt throttle closing which causes the wheels to try to spin up the engine. That can have the effect of causing one pair of tires to lose grip.

 

[haha]

I like AWD or 4WD for situations like when inexperienced winter drivers will stop going up an icy hill. With FWD, on an incline, more of the vehicle's weight is now biased toward the rear and the front (driven) tires are more likely to slip. With AWD or 4WD, you can pull out and get around them from a stop, even with marginal tires.

The same shift of weight to the rear on fwd cars makes driving in hilly, rainy cities like Seattle much more pleasant with awd. When I had a FWD car, I particularly hated starting up a steep grade and simultaneously making a turn. But my AWD car handled all this perfectly. Right now I am walking, but if I ever buy another car, it will definitely have awd and quality all season tires.

Ha

 

[GrayHare]

I'd bet the % of people in the US population who have actually mounted a car tire on a rim using only hand tools is very, very small. It's work, and quite easy to punch/pinch a hole in the inner tube (remember those?) while doing it.
Your dad made you a better person.

I did learn the primary reason to swap a car tire in that manner is to experience how good it feels when you don't have to. At age 10 it took me quite awhile to swap a tire, so my dad would busy himself with checking the brakes, bearings, etc. By age 14 I finally persuaded him to buy a used set of rims from the "junkie" as junk/wreck dealers were then called. In all seriousness, it was a good learning experience not only in car maintenance but also in wise use of money.

 

[pb4uski]

https://en.wikipedia.org/wiki/Lift-off_oversteer

I had this happen in March 1995 while driving a FWD Ford Probe (I remember the date because my uncle was dying in a hospital ICU, and I was in a rush to be there). There was a layer of slushy snow on the road, and I had just crested a hill, headed onto a downhill slope. I backed off the throttle, and as I descended down the grade the car began fishtailing. Ultimately it rotated 270 degrees and came to a stop in the center median. Fortunately I didn't hit any guardrails or slide into the oncoming lanes.

A couple years later I took a two-day driving course at the Bridgestone Winter Driving School in Steamboat Springs, Colo. That's where I learned the physics of what had happened to my car a couple years earlier, and how to avoid it.

When you back off the throttle, the momentum of the car shifts its center of gravity forward, toward the front wheels. That reduces the G forces on the rear wheels. If the road surface is greasy enough and/or the road grade enhances the weight shift, the rear wheels can break loose. Since the front wheels are maintaining their grip, the car becomes prone to oversteer.

When you apply the brakes to slow under those conditions, it balances out the car by reducing effective traction up front -- it performance driving parlance, it "settles" the car.

When you apply the brakes you also back off the throttle at the same time, no? If anything, applying the brakes enhances that weigh transfer from back to front rather than mitigates it (just like when you stop the weight of the car moves forward to the front wheels).

My point is that either lifting the throttle or applying brake will cause a weight shift forward and less weight on the rear wheels, but lifting the throttle will result in less weight transfer than applying the brake. The article that you cited is credible, but it refers to lifting in the middle of a turn, relates primarily to RWD vehicles (though it can occur in FWDs) and does not suggest applying brake in such situations. One would rarely be in the throttle in a turn in winter conditions (except with a FWD is you are losing control you might gently apply throttle in the middle of a turn).

What happened to you in March 1995 is that you were just going too fast for the conditions... whether you braked or not would not have made any difference.

I can see where backing off the throttle might transfer weight to the front wheels, but in order for that to happen you would have to be quite a bit on the throttle to begin with.

As you know, the key to safe winter driving in greasy conditions is subtle movements and that applies to right, left, forward or back.

 

[mountainsoft]

1. If you don't absolutely need to go out, simply stay home when it snows. Of course, this may not be an option if you must get to work every day, or if the snow storms last days or weeks. Even if we can take time off work, we always seem to run out of food right after a snow storm hits.

2. 4WD or AWD may help you get going but it does nothing to help you stop. All vehicles have all wheel braking.

3. Remember the only traction you have are the four little patches where the tires touch the road. If your roads are relatively flat and plowed regularly, you can probably get by with all-season tires. Otherwise, a good set of snow tires really helps in snow and ice. We have had good results with the Blizzak snow tires.

4. Ice is worse to drive on than snow. Snow tires can help a lot, but they can only do so much. Studded tires may offer some advantages on ice, but they are illegal in many areas because they damage roads.

5. Carry chains. Even if you have AWD and good snow tires, you may run into situations where you still can't get traction. Chains are about your last option.

We live on a rural mountain road in Washington state, about 1500 ft elevation. We often get snow up here when the roads down town are completely bare. We drive front wheel drive VW Jetta's and usually don't have any issues. Going "down" our steep mountain road in the snow is certainly much scarier than coming "up" the steep road. Stopping is more important than going!

We put Blizzak snow tires on spare rims for my wife's car since she has to drive to work every day. The spare rims make it relatively easy to swap them each winter and spring. I work from home so I can simply stay home when it snows. We carry snow chains anyway, as the plow doesn't always come up before we need to drive up or down the hill. Even with snow tires my wife got stuck on our hill a few weeks ago during a wet and heavy snowfall. We had to chain up to get up the hill.

I also bought a snow blower to clear our 150+ foot driveway, and the associated snow berm the snow plow builds in front of our driveway.

 

[Mr._Graybeard]

When you apply the brakes you also back off the throttle at the same time, no? If anything, applying the brakes enhances that weigh transfer from back to front rather than mitigates it (just like when you stop the weight of the car moves forward to the front wheels).

Braking reduces effective traction up front because brakes are biased to have their most effect at the front axle. Have you ever braked hard enough that the wheels locked up or ABS kicked in? You were sliding, but sliding in a straight line -- and to stop the skid, all you had to do was to stop braking. That's far more manageable than having the car trying to swap ends.

My point is that either lifting the throttle or applying brake will cause a weight shift forward and less weight on the rear wheels, but lifting the throttle will result in less weight transfer than applying the brake. The article that you cited is credible, but it refers to lifting in the middle of a turn, relates primarily to RWD vehicles (though it can occur in FWDs) and does not suggest applying brake in such situations. One would rarely be in the throttle in a turn in winter conditions (except with a FWD is you are losing control you might gently apply throttle in the middle of a turn).

No, numerous FWD and AWD vehicles can be prone to trailing throttle oversteer, like my Ford Probe. (In the dry, that made the Probe a fun car to drive.) The Wiki article notes that Consumer Reports panned the 2010 Lexus GX 460 SUV because of its oversteering tendency. Toyota recalled the vehicle to recalibrate its stability control as a result.

What happened to you in March 1995 is that you were just going too fast for the conditions... whether you braked or not would not have made any difference.

Your opinion -- you weren't there.

I can see where backing off the throttle might transfer weight to the front wheels, but in order for that to happen you would have to be quite a bit on the throttle to begin with.

At Steamboat we were able to produce trailing-throttle oversteer on a downhill slope at school-zone speeds.

As you know, the key to safe winter driving in greasy conditions is subtle movements and that applies to right, left, forward or back.

I agree with that.

 

[pb4uski]

Whatever.... I guess we'll just agree to disagree.

 

[Mr._Graybeard]

Whatever.... I guess we'll just agree to disagree.

I agree with that too.

 

[mountainsoft]

I can see where backing off the throttle might transfer weight to the front wheels, but in order for that to happen you would have to be quite a bit on the throttle to begin with. As you know, the key to safe winter driving in greasy conditions is subtle movements and that applies to right, left, forward or back.

We usually crawl down our hill at a snails pace in icy conditions (engine idling, just riding the brakes gently). However, on a few occasions we have hit spots where the car just starts sliding. Sometimes letting off the brake will let you steer again, other times it won't. I have been known to use the hand brake to lock the rear wheels briefly, causing them to slide and giving me slightly more control up front to steer. It's a last ditch effort in a very slow slide, but it has allowed me to stay on the road and not go in a ditch. The trick is holding in the button so you are just tapping the hand brake and not allowing it to lock. It takes some practice, and only works in very limited situations.

 

[Mr._Graybeard]

Here's an example how Blizzak tires can handle ice. The video was shot on a frozen lake near my home. Pay particular attention to the controlled stop the driver achieves at the end of the video.

 

[GravitySucks]

Bad advice in my experience.... lifting off the throttle allows the wheels to gain traction, not lose traction... and braking increases the risk of losing steering control entirely (albeit less so with today's ABS systems).



In over 40 years of winter driving in Vermont and Massachusetts I can't ever recall losing control when lifting off the throttle.

+1
Also, putting the car in neutral when you hit an ice patch ( like when crossing a small bridge ) foot off the brake will keep you straight too.