as a first impression, I'm thinking that there may not generally be a limit on tire size as in Diameter but there may often be a limit on how much if anything they can protrude from the fenders. There may also be a maximum height that the bumpers can be at. So, the 2 combined would effectively be a limit on tire diameter I guess.
good morning ,i am just rolling out of the bed ,here the law oblige to respect thefirst dimension of tires , there said we don't still respect it but we but it's dangerous in case of big accident (assurance).
In a very limited attempt to assist the Mud members on understanding the dilemma, I can attest to the fact that Europe in general and France in particular is somewhat anal about mods to vehicles, especially ride height. I believe Brunal is saying that the law in his area is that the tires must be the same size as the original equipment. I'm not sure what his original question was pertaining to, unless he was just looking for some common area of discussion. To answer the question, in Arizona there's no limit that I'm aware of, but I've heard of some states or cities that do impose restrictions, although I don't recall ever hearing of a place in the US that completely forbade changing the tire size from original equipment specifications.