Awhile back I noticed that my well worn tires were seemingly out of balance but I just figured maybe also it might be a tire going bad and they would be replaced anyway. In the process of replacing them, I noticed a heavy accumulation of dirt and other material at the edge of the rims and it was sandwiched in there by the hubcaps. There was at least a 1/4" of stuff and I believe that had to affect the balance of the tires. So in the future, when I wash the car, I'm going to hit the outer edge of the rim/hubcap juncture with a strong blast of water. And when I rotate the tires I'll check and clean that same area to prevent this out of balance condition. I have a 2008 Prius Touring.
well when tire shops balance your wheels they only put a little bit of weight to balance them so having a lot of caked on mud at the outer rim of the wheel cannot be good for them. So yes when you wash your car don't neglect the wheels, wheel wells and undercarriage. You should expect front tires to wear faster than rear tires since they are used for both powering and steering the car, but if you notice a difference in wear between the left and right side, that is usually indicative of a worn strut.
thanks for the post, now I want to go watch a young and sexy Marissa Tomei in My Cousin Vinny talk about mud getting stuck in the tires.
Which is why myself and many other's here removed the hub caps long ago. The wheels look 100 times better and the edges don't get rusted. You have to take the caps off to clean them. A strong stream of water will not do it.
OP has a touring, while I agree owners of non-touring prius should remove the trim rings, I think the touring wheels look better with the full wheel covers on, especially considering the wheels underneath are dark gray, not black, and have no center caps.
