Lets see your winter tire set up!.

[SGAveoGuy]

This is a great posting. It's all about tire inflation pressure here. Basically, any tire with a good tread life (minus a racing tread, and rubber band tires), can be used, as long as you LOWER the tire pressure. This will allow the tread to squish out, form to the surface, and grip better before spinning. Why do you think ROCK CRAWLER'S run low tire pressure? -- To wrap that tread 'around the rock's surface, spreading the contact patch, therefore improving GRIP. Best way to figure out your preference is lower the pressure to 30lbs, and go from there. If your not gripping, lower each tire equally by 2lb. increments until you have the desired traction. Too low, and you may pop a bead, destroy the sidewalls, or even bend a rim. I wouldn't go below 22# for everyday driving.
Next time you guys purchase a set of NEW cheap ass winter treads, have them 'siped'. It's an additional set of cuts made across the original tread pattern, which allows the tire treads to spread like individual caterpiller legs, and grip better. Cost is about $7-10 bucks a tire.
Don't forget to air your tires back up to at least 35lb in the spring, or if your doing alot of higher speed freeway driving. Your mpg average will suffer, and so will your tires.

[ontarian_frog]

Whoa, not recommended. The lower pressure in the tires will make your car hard to drive at highway speeds and you'll damage your tires and have to replace them early, not counting the fact you'll loose tons of mpg.

Best thing is to buy a good tire, inflate it properly. You'll be safer, the tires will last longer and you'll still get good mpg.

I don't know where you plan to drive like that (Antartica?), but lowering the air pressure to 22lbs is plain stupid for everyday driving. You won't be running on the thread, you'll use up the sidewall, which has no thread and won't grip as good.

EDIT:

The reasons rock crawlers can run such low psi in their tires are:

1. They don't do more than 20mph. Even that is fast.
2. They don't put 15 000 miles on the vehicule a year.
3. They don't run on paved roads.
4. The thread width and sidewalls are made for those conditions. Those guys worry more about a punctured tire than they do about uneven wear.

[exodus]

I've always lowered tire pressure for snow, less for a proper snow tire. Just keep it off the sidewall and it should be fine.