I'm a little confused by this whole issue. Several posts on this site say the rule-of-thumb is the tires should be no more than 2-inches wider than the rims. However, I took my 4-inch rims to a reputable national time store and showed the wheels to the sales guy at the front desk. He said he would have no problem mounting 215x85xR16 radials on the original wheels. A 215 tire is 8.4 inches wide! He insisted the 40k warranty would still apply. Did I get some bad advice? Also, the previous owner of my truck installed 245x70xR15 radials on 6-inch rims. The 245 tires are 9.6 inches wide. These tires and wheels are currently installed on the truck. The tread is wearing evenly and the truck handles well on the road. So, what gives??