I guess winter is here with a vengeance. It was -36C when I got up yesterday morning, and had warmed to -33 by the time the kids went off to catch the school bus. Sigh. Of course, once we went into the deep freeze, something went wrong with my car. At speeds above 60 km/hr, the Mazda would start to vibrate very strongly, getting worse with increasing speeds so that it seemed the whole vehicle would shake apart at 80 km/hr. Since I spend a lot of time on the highway, this had me seriously freaked out. I had visions of spending many hours at the dealership while they figured out what was wrong. Sigh. Still under warranty, but still...... what a pain. Although it seemed unlikely that the tires would be balanced on Friday and unbalanced on Sunday, I started with Costco to balance the tires, since this is where I bought them from. Turned out that when the tire guy took my wheels off, great quantities of ice came out of the wheel wells. Once this ice was gone, voila...... driving returned to normal. And it didn't cost me anything, if you don't count the two hundred bucks I spent while I was killing time waiting for my car. ;-)
Anyway, I guess this is not uncommon, so if your car starts to shake and shimmy after a big snowstorm, it's probably ice in your wheels. I guess the heat from the brakes melts the snow, which reforms into ice at some point. And if there's lots of it, and it's not even, the wheels are seriously unbalanced.