fiftyfeetup,
i have the 30x11.5x15 and they only slightly rub when the wheel is fully cranked and i am in reverse. there is plenty of clearence with the frame so you may only need to slightly trim the inside corner of the plastic on the bottom of the front fender. i have only been offroad once but, i made it up a hill that i could barely walk up without slipping (wet clay) and i didnt have any speed (4x4lo, 1st gear). but i only made it up once, so maybe it was a fluke. but i like them.