I'm trying to get rims for my car. The rims I want are 17 x 7, apparently. I have the stock 245/45R17's on my car now. Obviously they're 17", but 17 x what? The guy who has my rims said that my tires are too big for the 17 x 7. If that's so, what tire size would I have to have for them to fit? Wouldn't I just go one size smaller? Someone help me, please, this is so aggravating.