So I have the 245/70-17 stock rims and tires at the moment. I don't really have the cash right now to get new wheels too (plus i haven't seen any i really like). So I want to put some larger AT tires on the rims I have but i don't really understand the technical details of tire sizes and what can fit on what. Not only do I want them taller, but I want them wider as well. Hence the 275 request below. Is it possible to put a 275/xx-17 tire on my 245/70-17 rim? Im not really sure how to calulate the XX.