I sell tires for a living. I can attempt to answer any tire-related questions that you may have for free. In the unlikely event that you're reading this AND car shopping, allow me to provide a smidgen of advice:avoid cars with low-profile tires or "optional" rim sizes. That 18" may look cool, and it'll be amazingly responsive, but that's gonna raise the price of your tire by about $50 apiece and take the smoothness out of your ride.
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