The 10.50 inches is the tire's advertised width, usually taken at the tread, not the sidewall bulge. And the 15 is the size of the wheel it's designed for. So, in this case you've got a 31-inch ...

Pro Comp is noted for its tough tires, and they don't get much tougher than these 37x13.50/15 XTerrain and LT 325/80R16 (37x13.50/16) Xtreme All Terrains. How about three plies of high-denier ...

Well, this face-off is all about the off-road experience, and both the Land Rover Defender and Toyota 4Runner TRD are legitimate and legendary when tire meets the muck.

There are still big differences in tire designs for on-highway and off-road tires, but newer designs make it possible to do a little of both.

The special ZR2 off-road version of the Colorado mid-size pickup featured front and rear electronic locking differentials, spiffy Multimatic shock absorbers, a lifted body and big knobby tires ...

Well, this face-off is all about the off-road experience, and both the Land Rover Defender and Toyota 4Runner TRD are legitimate and legendary when tire meets the muck.