You can go to 17" wheels and use a lower profile tire, one size down and end up with the same overall diameter of the wheel / tire together as what you have now. In other words, the lower profile tire would have a slightly smaller distance between the wheel and the pavement. Hopefully that makes sense. It's nothing unusual, there are all kinds of variations that can be done. For me I wanted a larger overall diameter by using a slightly higher profile tire, just one size larger, made a difference of about 1.5". If you reduce the profile by one size then increase the wheel size to 17" you will end up with an overall diameter of only approximately 1/2". If you want to know more or need some help choosing, just send me a private message, I'll send you some good info. Cheers, Ken