BlueRidgeRick

Here in Atlanta GA we seldom have snow and when we do I stay off the roads as it melts a day later. I do have a mountain cabin which gets snow but if snow is in the forecast for the weekend we just stay in Atlanta. However, 6 years ago we were in the mountains for a week beginning with Christmas Day. Three days later we got 10" of snow and I barely got around in a Lexus GX. I then bought a pair of Thule XG-12 snow chains but thankfully have never used them. I now have a Q7 and the chains will fit. I'm curious about an informed opinion on which 2 wheels to put them on to get down a steep 3 mile stretch of gravel road. Once I'm off the mountain the roads are cleared with county snow plows and I won't need chains. My thought is the front left and the rear right. The Audi dealer employees have no opinion as no one has used chains.

lentiman

Why would you be using chains on an all wheel drive vehicle? Do you have summer tires or all season tires on your wheels? See what the people from the land of maple leaves say but it's either none or all 4 wheels if you're using AWD.

Canadian Lurker

In my area of the land of maple, I use winter tires but many stick with all-seasons. Where chains are called for or are more commonly used, it's recommended that you use 4 so that traction, steering, braking is not compromised by the wheels with no chains. If you only use 2, you'll be compromising.

That said, if you must only use 2 chains then they should only go on the back. You always want to have the best grip/traction on the rear otherwise you risk having the back end come around on you when you make a turn, or have to brake hard. It's the same idea if you are replacing just 2 tires, the new ones need to go on the rear. Doesn't matter if it's FWD, RWD, or AWD the tires/wheels with the best traction always need to be the rears.

norwestie

For your example, I would put the chains on the front tires. Most of the braking power and all of the steering is on the front. Another consideration is ice. It makes no difference how many drive wheels you have or whether they are on the front or rear. If there is no grip, you'll slide. There was a video I just watched (on autblog.com, I think) of a drag race between an SUV on all season tires and a rear drive car on snow tires. The SUV lost big time.

BlueRidgeRick

What happens in GA is that we get snow but the first night is cold enough to keep it snow. The next day between the warm ground and strong sunlight it turns to slush. The night brings hard freeze and everything turns to ICE. Many Northerners who are new to atlanta say "No Problem, I can drive on 3" of snow" not realizing that yesterday's snow is now ice. I don't know of anyone who can drive on ice with all season tires. We only get traffic stopping snow about every 3rd year so no one is going to the trouble & expense for winter tires.

Canadian Lurker

FWIW, getting an additional set of winter tires is somewhat cost neutral as opposed to simply being an added cost. Let's say you use winters from Dec 1st to March 1st, assuming that's when temperatures regardless of precipitation are at or below about 45F. That means your summers or all seasons are not accumulating miles for 25% of the year, which pushes out the need to replace them compared to driving on them year round.

So, over say 6 seasons running winters you'd delay replacing your other tires by 1.5 yrs. of course YMMV.

Back to the chains question, here's a good summary:

Back to the question, what happens when you mount tire chains on either front or rear:

"On 4WD vehicles:

• Snow chains mounted on all 4 with 4WD/AWD - ideal lateral stability, perfect acceleration, crisp steering, super braking. However, part time systems will show some understeer (turns are wider than intended). Full time 4WD systems are best. This is what everyone should have for snow and ice. Be careful anyway.
• Snow chains mounted on front axle with 4WD/AWD - good acceleration, good steering, good braking. However, since the rear wheels have no lateral guidance, the rear end might come around - fast. Not good. Feather your brakes. Go slow.
• Snow chains mounted on rear axle with 4WD/AWD - good acceleration, lousy steering (no lateral guidance), marginal braking (remember, 80% of brake force is created at front wheels and without chains that ain't happening). No fishtailing. Best compromise for 4WD with only one pair of chains. Go slow."

Snow tire chains - where do you mount tire chains on a 4 wheel drive - front or rear?