I'm going to get new tires for my E36 328i in the near future and I noticed that for 17" wheels, BMW recommends 235/40R17 tires for my car. The OEM tires (no plus sizing) are 205/60R15. When I calculated tire sizes I find that 245/40R17 tires are a much closer match than 235's. Why does BMW recommend the 235's? Is there a problem with 245's being too wide a tire and thus require modifications to the wheel well? Would either tire work just fine or should I go with one width over the other? Thanks.