Driving in snow - 2wd or 4wd
 

This question is for all of you folks up North that get that cold white stuff that falls from the sky :

How would you compare the drawbacks of driving in the snow with a 2wd, versus 4wd vehicle ?

We all know that your FE takes a hit, but is it worth it for the few times that you have a heavy blizzard ?

Thanks

This is my first winter in Canada. We have a Civic and a Rav4. I'll let you know how they compare when we get a decent snowfall. :D

With my Impreza or the wife's Outback having snow on the ground is one of the rare opportunities for wheelspin and maybe some power on oversteer.

My Crown Vic and Lincoln require a healthy dose of ballast in the trunk in order to get anywhere. Both are in desperate need of a traction lock or other diff.

They are all on all-season tires year 'round.

2WD when you don't need 4WD an 4WD when you do. The only real time you need 4WD is when you are stuck with 2WD.

It couldn't be simpler

Living in Maine all I ever had was RWD vehicles.
I have found the RWD only suburban with open diff is almost always enough.
To make it enough with out going 4x4 I got an ARB air locker.

On road, you would never need 4wd. Someone with awd will probably have it engage but honestly, if you're driving so hard that you need 4 wheels to move forward you're probably driving too hard.

I have never been stuck with fwd or rwd. My mother in law got her 4wd nitro stuck last year, tire choice is hugely important and not necessarily snow tires.

From what i have noticed, typically tires that perform well in the wet will do well (relatively) in the snow.

Cooper discoverer htp, khumo solus kr21, general gmax as-03. After a few snow falls i will know if the michelin latitude are any good, should be.

There are many reasons fuel economy takes a dive in winter. First is the lower BTU output of the fuel. Second is idling and longer, richer cold starts. You can counteract tires by getting Nokians. They get better mileage than most summer tires for their all weather and winter tires. The advantage of winter is that you can really get aggressive on your grille block in colder temps as long as you're still moving - or you can always throw the heater full blast and crack open the windows.

The only time I could see needing a 4wd is for ground clearance. I've taken my fwd car and rwd truck on the Coquihalla in winter with Nokians and no issues. They're the best insurance policy.

:-)

Good winter tires beats 4 wheel drive. In snow, turning and braking are more important than acceleration, so winter tires are the only thing that helps with all 3.

I have driven in New England for 38 years, and I have had rear wheel drive and front wheel drive. Starting with my second car (1970 Volvo 144) I have always had 4 winter tires.

I'll second that. I've driven through at least 38 snowy/icy winters as well and never had 4wd. I wouldn't want it either. They waste gas all year round for starters and for the most part, are not any safer on the road. The exception to that might be the AWD systems from Subaru and Audi but I've never had a chance to try one. I've driven 4wd pickups for work and I found them horrible. If I lived up some mountain road that never got plowed in the winter I might feel differently, but I don't. 4wd does have its place, I just don't think that it is as important as many people think. I don't know how many times I been out on the highway in a snow storm and the majority of vehicles in the ditch are SUV's. I'll take a FWD car with a good set of snow tires over 4wd any day.

What is your goal?
4 wheel drive will let you feel confident to get going on roads that you can't stop on.
4 wheel drive should be saved for getting unstuck.

Most winter accidents are from not being able to stop, two and four well drive vehicles have the same brakes.

I have no issues driving my Honda civic with snow tires to work where the last mile takes an extra day to be plowed and I'll push snow with the bumper.

I notice that (at least as far as I can tell) everyone who says this seems to live in the flatter parts of the world. And it's certainly true that I learned to drive in such a place (before anything but Jeeps had 4WD) and people managed to get around ok. But head up a nice, steep mountain road and you're likely to get nothing but wheel spin.

My vehicles have always had studded winter tires, whether Fwd, Rwd or 4wd. Personally, I prefer 4wd as the amount of control you have in all maneuvers is just that much better! Studded Hakka 8's!!!

http://i1002.photobucket.com/albums/...022_113250.jpg

http://i1002.photobucket.com/albums/...203_115044.jpg

http://i1002.photobucket.com/albums/...ps987d4454.jpg

http://i1002.photobucket.com/albums/...0117-00892.jpg

Live where it does not snow? :)

My dad's F150 must have had summer tires, but I tried to be careful, and found myself sideways before the end of the block. There was an ice patch and I came back even slower, but with plenty of stuff from Home Depot, so there is that.

I just tried to pull over in my Forester and my car went off the road and got stuck. I figure that once the right wheels were on snow, the difference in traction got me.

Weren't we just discussing (in the Jeep thread) that armor makes you stupid? :)

I'm happy with FWD. A set of snow tires is even better. 4WD will help go faster but does not help you stop. For most people save the gas money year round and buy a set of mounted snow tires.
My anecdote is from when I was driving across NH for school everyday. My little CRX with snows had no trouble all day long but I passed more than 10 4WD SUVs spun-out in the snow banks along the way in one day.

AWD can get a vehicle more stuck than a 2WD car. I once spent 5 hours digging my Legacy out while wearing jeans and a t-shirt because I plowed the road with my bumper until high-centering on the snow. All I had was a screwdriver to dig out with and no gloves... not the brightest moment in my life. Then again, I didn't expect the road to be full of snow that early in the winter.

Thanks for the replies guys.
Let me add to the question : Does a 4WD handle any better than a 2WD in snow ?
For example, when going around corners.

Main concern is safety.
My friend up in Canada is looking at buying an suv - a new Honda CR-V , a Jeep Puberty ...er Liberty , and other smallish suvs.

My question mainly pertains to SUVs.

Only if it is fulltime 4wd (locked) or a good awd system. Most awd only drive the other two wheels when needed. Snow tires will make the biggest difference.

All vehicles come with 4 wheel brakes ... even FWD cars! I'm more concerned with stopping than going!

The CR-V AWD system will handle much better than the part time 4WD system in the Jeep. The part time system found in most Jeeps and trucks is better for off road at slow speeds. It tries to make all 4 wheels turn at the same speed, even if you are turning .. .which means they will get unpredictable when you are trying to do anything other than go straight while applying power. A "full time" AWD system will allow the wheels to all turn at different speeds when applying power.

My fwd jetta, with Blizzak snow tires, does all around noticeably better than my Subaru outlook without snows.

Snow tires for the win.

Exactly what Neil said. 4 wd might get you going better, but won't help you stop or steer better when conditions get ugly. Honest to God snow tires do all 3, starting, stopping and steering/turning.

The only time 4WD improves cornering ability is when applying throttle while in the actual corner. Basically, 4WD is only an advantage when more traction is needed to go, but does nothing for coasting and braking.

As far as the Puberty is concerned, the 2WD can get unskilled drivers into trouble quickly on slick surfaces because it is rear wheel drive. The back-end will toss out and put the car sideways, especially with the torque that the Liberty motor has. It would be a good idea to engage 4WD in the Liberty whenever conditions are slick to keep the rear end from trading places with the front end.

For best handling in snow, choose the lightest vehicle. My Liberty AWD could run circles around my friend's Ranger 4x4. A CUV or sedan would handle better, but have less ground clearance. Ground clearance is only a concern when traveling on roads that do not get plowed. There is a trade-off of having a low center of gravity (better handling), and being able to drive over taller obstacles (deep snow). My legacy had low clearance but could still push uphill through quite a lot of dry snow.

http://i7.photobucket.com/albums/y26...9899ot1lsi.jpg

Locked differentials will handle corners worse than unlocked. It will have more traction for straight line acceleration, but will give a bit less traction if powering through the corner because the wheels will be forced to slip.

The difference in grip level on snow and ice between the all weather tires on my previous car and the Continental TS 810's on my Insight is quite large.

I saw a car ahead of me slip off the road with no apparent cause but for the icy snow. When he got going again I waited at the spot where he started his slide, then launched my car trusting the traction control would kick in immediately as it would have insufficient grip on the ice. But it jumped forward almost as if it were on dry tarmac.

Three years onwards, the thread depth halved, I feel there is not as much grip as when they were new. So that remains a point of concern; don't run them down too far or they lose the very property you bought them for.

Where I live, (the great flatlands of Ohio USA) 2WD is more than capable of getting around in just about any weather. The biggest traction factor is the TIRES. A good set of all season tires with decent tread depth is usually all that is needed. Winter (M+S) tires if you want gonzo good traction. I actually prefer 2WD rear wheel drive with Traction control and stabilitrak turned off, to fishtail all over the place like a dirt stock racer. I ALWAYS go out on the first snow of the season and renew my winter driving skills in an empty parking lot and/or abandoned streets. Better to know what the limits are before you need them.
I used to believe 4WD made no difference on stopping till I actually owned one. Now I know it helps. With 4WD you are LESS likely to lock up the wheels since they are all tied together. With full time 4WD enabled, the Car/truck will also want to track straight making low speed turns almost impossible. I find driving with 4WD enabled annoying, because the overall traction and control is TOO good compared to everyone else around. It comes in real handy when pulling stuck people out of their bind.

Cheers!
LitterBug

2000 Insight (commuter)
2009 GMC Sierra (really, really, really bad weather)

As many have said, tires are really important. A good illustration of this can be seen at https://www.youtube.com/watch?v=GlYEMH10Z4s

In order of priority I would put tires first, traction control / stability control second, and 4WD third. The point made earlier about driving in hilly areas is a good one though. That isn't a problem I face, and I may view things differently if I lived in the mountains.

Another point worth mentioning is that tire pressures are more important in winter. In summer we (aiming for economy) rarely if ever approach the traction limit of our tires and can over-inflate the tires without serious consequences. This is not true in winter. Generally I run much lower pressures in winter and if necessary drop them very low (maybe 10 psi) to get traction where others get stuck.

In very slippery conditions, FWD/4WD can be worse than RWD. Applying power to the front wheels can get them to slide, and sliding tires won't help you turn. Keep your front tires rolling, and you'll have more control. FWD/4WD can help you pull the front end around a corner by applying power in moderately slippery conditions. I'd say it's a wash, but personally prefer RWD in snow.

I think that if you need 4WD or AWD for snow, you shouldn't be driving in snow...

I'll reiterate what everyone else said. Tires are far more important that what wheels are being driven. Get good snow tires (ideally on a spare set of wheels that you can swap out every spring/fall) instead of relying on all-seasons and you'll be able to handle anything you encounter on a road.

What everybody else said.

Plowing snow with the front bumper can plug the radiator with snow and cause overheating. It happened to my sister once up in the Michigan Upper Peninsula.

Percentage of weight on the drive wheels is important. A FWD car with one person may have 60% of the weight on the front wheels, and excellent traction.

My 2WD pickup with topper, bed mat, trailer hitch receiver, toolbox, and box of chains in the back has about 50% of its weight on the drive wheels. Traction is adequate, and I have chains when needed (about once every two years).

A 4WD pickup with one person and nothing in the box will have as little as 40% of its weight on the rear wheels. Traction will be poor. Four wheel drive trucks have several hundred pounds of 4WD stuff, with that weight centered over the front axle. That shifts the weight distribution enough that 4WD trucks need 4WD in snow, while 2WD trucks do not need 4WD in snow.

I have over 40 years driving experience in snow country, and have never owned or used 4WD. Never needed it, either.

Loved my Subaru. After nine winters with it I was uneasy with the blizzard right after I bought my Fit. But after a few days I was back to passing Jeeps.

We all got where we were going back when everything was RWD. FWD made things a lot easier. AWD? Getting started, engine braking and lane changes (when there's a ridge of snow in the middle) are a lot better, and that's about it.

Did that with the Focus a few years ago. Didn't even have a grille block on! Crashed through a pretty big snow bank blocking my parking lot then got on the highway. The overflow tank was overflowing.

Tirerack.com did some tests a few years back with tire pressure and traction on snow, they found that with low pressure they lost traction and recommended full pressure.
My snow tires have a 51psi sidewall rating and I keep them at that pressure.

My only real experience with 4wd was my grandfather's old subie wagon. This was back in the 80s. It was a late 70s model. One of the first subie 4x4s. On regular tires, thaat damn thing would go anywhere!

Today, most cars with fwd and traction control will get most anyone anywhere they need to get. If not, you really shouldn't be out anyway. The only way I could see buying one was if I lived in a very snowy, very hilly area AND I had the need to get out when things turn to sheet.

Also, not all TC is created equal. The OL's 2003 Odyssey is a beast in the snow. The TC makes it pull like it has a locked diff. My 2009 Sonata's TC is complete garbage. Most of the time, it just kills power. I have actually turned it off in disgust to be able to get up a hill.

I live in the mountains of Montana and regularly drive all 3 possible types a most every day, Fwd, Rwd, and Awd. Rwd is really not ideal. Around town knowing I might have to chain up is a pain and slows me down considerably. Not I'm being safe slow down but the aggravating I can't drive all my normal streets or park where I need to slow down. The Fwd works much better but we still use good condition real studded snows to be able to get up our road everyday. The AWD is even better and has worn snow tires. It is some ways harder to drive the AWD as it can drift the back end (oversteer) where the Fwd will only plow the front end (understeer). The AWD can do both but the oversteer is what surprises people who aren't used to it. The Rwd can do both also assuming it's not just sitting there immobile. Around here a 2wd truck or SUV is not worth buying as the resale is much lower if not impossible. I had to ship my last 2wd pickup to Alabama to get it sold and still took a bigger hit then if I had just paid the $2000 more for 4wd in the first place. Rwd SUVs are even more difficult to get rid of as most are looking for 365 daily driver family rig. A 2wd pickup at least is still a good boat or camper hauler in the non winter months.

Being able to stop is more important then being able to go, 4 wheel drive hurts stopping distance, if for no other reason that it makes the vehicle heavier.

I just added towing to my progressive insurance policy, $1 per month and I can use it 3 times every 6 months.

Most systems "control" traction like people try to control crime. They don't want it getting out of hand. Wheelspin detected? Kick in the ABS. Problem soved: no more wheels spinning!

In any snow at all, or in the wet in certain locations, turning it off is just another part of my routine. I'd rather be a little busier than have the shock of brakes being applied for me when what I want and am expecting it the exact opposite.

Correlation is not causation. Most 4/AWD rigs are just plain too heavy for "stopping distance" to be anything more than a sick joke even before the extra drivetrain gets counted. And speaking of dodgeball victims, they invariably have automatics. It's a trifecta of excess weight, lack of gear control and sloppy power input.

My Subaru was the bomb. Yes, the drivetrain (and the turbo...:o) held down my gas mileage. But with a manual transmission, control of the driven (count 'em, 4!) wheels was unsurpassed. Slightly lifting the throttle introduced deceleration evenly in all four corners. Coming off entirely or downshifting let you do it with more force. With the engine it's all smooth and controlled, reversible with a thought- your foot never leaves the pedal. Not as clumsy or random as pads clamping down on rotors; an elegant system for a more civilized driver.

Stopping distance? You can slow well enough to not need to stop.

I think we drove the wife's Murano in 4wd less than 10 miles in 32k miles.
RWD is not bad on snow, but ice-freezing rain is another thing altogether.

regards
mech

I had a look at Tirerack.com but I could not see the test you mention. Do you have a link to it? The result directly contradicts my own experience and I would like to look at the test to try and understand how/why they reach that conclusion.
One issue is that winter conditions can vary so much - far more than summer conditions. Perhaps in fresh deep snow higher pressures may be better; I am not sure on that and have never tested it. For packed snow or ice I have always found low pressures to provide much better traction.

Note that studded tires beats everything if you are on ice, but are illegal for most states and most people. In Michigan, the postal delivery folk are allowed to have them...

Just a quick "ditto" of others' comments that 4 winter tires are hands down the best choice no matter which or how many wheels are driven.

First you knock AWD, then you sing its virtues? I'm confused.

Depending on which Subie you had you may have had 3, or possibly even 2, driven wheels. Center diff might always send torque front and rear but front and rear diffs are not all LSDs. My STi on the other hand... w00t! That car was so much fun in the snow it was probably illegal.

My winter tire cautionary tale occurred in a different Subaru, with winter tires (my first-ever set) and 3-wheel drive. :p We were coming back from the airport on a wet winter day. Everyone was barreling along in spite of the conditions, as usual. Crossing an overpass I thought I felt the car slip a bit, as if the bridge surface had frozen over. I looked up the road and sure enough cars were spinning every which way on the next overpass, bouncing off the guardrails and one another. I did not feel safe making a panic stop due to the traffic volume, so I picked my way through the ongoing carnage. Got out the other side unscathed, looked at my wife, and said "that's it - winter tires from now on".

I have a 4WD Tacoma now. The 4WD is nice on snow-covered roads but nowhere near as effective overall as my AWD Subies. It's designed for ultimate offroad traction, and the differences are noticeable. Snow-covered woodland trails, on the other hand, are the Taco's happy domain.

I was knocking the overweight SUVs that tend to be what gets 4/AWD.

In a small or midsized car it can be as great as I said. The only real knock against AWD is that while it's better than FWD, FWD isn't actually bad so AWD doesn't give you all that much- I've never decided to stay home because I "only" had FWD.

My Subaru had the "symmetrical" AWD, which I think was all 4, all the time.

I've seen some amazing feats of driving in the snow with fwd being able to vector the drive wheels up hills but I've gone tush-up in a ditch with my old Subaru Forester because I broke the front loose trying to turn and accelerate out of my driveway on ice. My kids still bring up the amazing donuts we could do in that Forester in the snow. Good times!

The video a few posts back shows how snow tires have twice as much grip on ice as all weather tires, and that's good. Studded tires do even better on ice, as mentioned.

Where snow tires really stand out is (predictably) in snowy conditions and especially just below freezing, on a road with a layer of hyper slippery flattened snow and some fresh new flakes on top - conditions all too common in our moderate winter climate.

That surface is very treacherous with ordinary tires, where the snow fills up the tire thread so the wheel is like a solid ice disk, making the upper layer of snow underneath melt under the contact pressure. Grip is even lower than on ice.

The thread of snow tires though has small ruts and soft rubber.
This prevents the snow from packing solid in the thread. Thread pressure will still melt the top layer of snow, but that escapes into the thread recesses.
Moreover, the finer detailing of the thread means it matches the small aberrations in the road surface better instead of riding and gliding on the tops.
It does not just have twice as much grip, like it does on ice.
It has ten times as much grip or even more.

I have scared myself so many times before with all my previous cars and their all season tires, that I have difficulty assessing the grip level of my current winter tires.
I cannot bring myself to exploring the limits as they are so far beyond what I was used to.

There are very few states that outright ban studded tires, and of those the laws only apply to residents of said state. The other states only have date restrictions.

http://www.rma.org/tire-safety/seaso...e-regulations/

Never had a problem driving in WA, OR, or CA outside of the permitted window.