This tire calculator is even better.

 

I see the same thing all the time on the Jeep sites I frequent. People throw 33x12.5/15 tires with 15x10 rims on their Jeep with 3" backspacing and wonder why they tear their fender-flares off because "the guide says 35x12.5s fit with the 5" of lift I've got". Or they put 33x12.5/15s on stock 15x8 rims with their new 4" suspension lift and wonder why they tore up their new tires on the suspension components while turning (the guide said 4" of lift would clear 33x12.5s on 15x8s). Shoot, the right backspacing and rimwidth can help you fit 33x12.5s on a Jeep with NO suspension lift.

The same general idea applies to most vehicles. If your tire tread sticks much further out and up than stock, you're possibly gonna hit the fender lips. If the tire tread sticks much further in and up than stock, you're probably gonna hit something when you turn. Pick the right rimwidth, with the correct backspacing or offset, and your possible selection of tiresizes will fit much better.

 

thread from the dead...Jesus McTits...