Very light snow is all i would do with them. I had all seasons on when i went last year. The guy at the checkpoint told me ".. oh you are AWD you wont need to put your chains on." I'd never taken the wrx in the snow so didnt know what to expect. The guy was incorrect. Spun the car around three times. There was another AWD vehicle in front of me about 50 yds and we lost it in the same areas. We were lucky enough to maintain and get down the mountain. compressed snow = ice. The hockey puck comment is an understatement. On flat land you might be fine. On a downhill with anything other than optimal situation...stop and go for example, it's easy to confuse the awd even as symmetrical as it may be. Your car will want to go in the direction of motion due to inertia. You can easily drift off the road and down the mountain even at speeds of less than 5mph. It's a creepy feeling when you slide so slowly and are just along for the ride while countersteering and other efforts to rectify are futile.

Avoid touching the brakes unless you have to. Keep your car in low gears and let the engine brake bring you down. If you have an idiot behind you, use one of the turn outs to let them pass. Don't let anybody hurry you. In snow I found that AWD doesn't mean crap without appropriate tires. I saw a wrx wagon completely destroyed on the way down the mountain. Could have easily been mine. My recommendation is to buy a set of stockies and put some blizzaks on them. I would not recommend chains as they will only be on one set of tires, potentially throwing off the tire radius, which may have impact your dif longevity.

This article on Edmunds is really good. Check it out for a guide on snow driving.
http://www.edmunds.com/ownership/how...3/article.html
"Be informed: Regardless of whether your vehicle is rear-wheel, front-wheel or all-wheel drive, the results of a loss of balance are the same"
My .02
-J

 

Let me break it down for you:

1: Summer tires get ROCK HARD when it is cold. This means their soft compound does not adhere to the road surface...even when it is just smooth pavement.

2: Summer tires have far fewer tread grooves, which means they fill up with ice and snow faster. They are not as good at evacuating the grooves either. End result, you now have rock hard tires filled with snow and ice.

3: Summer tires are flatter and have far stiffer sidewalls. This means they do not flex and conform to non-even surfaces.

In the end you might as well put each tire on a sled and push it down a hill because you will have about as much direction control...not to mention lack of stopping power.

Little story for ya. Last winter I was running my Z1 Star Specs right after my 6mt swap. I had to make a quick run up the mountain to work this same week of December. I thought it would be ok if I took it real slow. Man was I wrong.

I hit a 3-4 mile piece of road with hard packed ice, and fresh snow on top. I came around a slow downhill corner going about 10 mph when my steering gave out. I tried to pitch the car and give it throttle to no avail. I had about a 4 second slow motion ride into the embankment. Luckily I only destroyed my front bumper, fender liners, and trampled my grillcraft lower grill. Luckily it was a very low-traffic mountain road.

I have been in Tahoe the last 2 Thanksgivings when it snowed. Last year I had some good all seasons and I made it out of about 1 foot of fresh snow with no issue. This year, I was on my Dunlop RS-2 when it snowed Friday night/Saturday morning. I took a test trip down to the Kragen figuring I would decide whether I needed chains on the 2 mile round trip. Well, I bought chains. As has been mentioned, and as I have learned, it is better to be safe than sorry.

 

Don't take my word on it, but... I have driven from the bay to wyoming and back in the middle of january running some falken summer performance, and without fail @ -40 F. Lowering your psi in the tires to 25 or so will greatly improve your footprint and provide more traction. Your tires might jacked up as far as performing again on dry conditions, but I never really noticed. The main thing to be carefull about is going downhill on crap tires. Try to do as much trans braking as possibly, no matter what tires, that will slow you down much faster than the crap traction control. Again don't take my word on it, but it is possible just to make a point, and unless you have a ton of experience driving on ice and snow, don't try it.

 

Last thing. If you do it, please do not post an "I crashed my car driving to Tahoe on Summer tires. HELP!!" thread

 

I've mentioned this in many, many other threads but two sets of wheels and tires (winter and summer) is the only way to go for the serious Tahoe Trekker. Sure all seasons can get you there but a dedicated set of rims with snow tires will get you there with confidence. The feeling of a Subaru with snow tires is awesome, amazing performance whether it be speed, braking, regaining control, etc...

 

my friend when to tahoe in his sti on stock re70's and the first thing he did when he came back was look for a second set of wheels for snow. he endded up perpendicular to the highway going ~25mph.