It mostly depends on HOW large the new tires might be.



The easiest way to visualize this is to simply use a block of wood or rooled up newspaper, etc...of the same thickness as the added tire...and pass that between your CURRENT tire and the stuff that tire might hit.

You do it at straight, and turned tire positions, and if thorough, at stuffed positions too...and its pretty reliable.

So if you have 33's, and are contemplating 35's...a 35" tire sticks out 1" more than a 33"...so you pass a 1" thick object around the 33" tire, to see where a 35" tire would be at, etc.