I am also one of those running on big tires/wheels combo but probably one of the lucky ones 'cause have not encountered wheel bearing problems since I own the car for three years now and app. 100k miles. And I am running 18" 225 wide tires, only in the summer though. Mind you I check the bearing play every spring and relubricate them as well . My friend also drives a 300E with 17" wheels and 215 tires and may have changed the bearings once since he owns the car, I'd say for 4 years, I have to double check with him. Hope this helps somewhat.