The 33x12.5R16.5 tire size is a light truck tire that’s a common fit on 1500- and 2500-series light trucks, especially when you’re looking for some extra ground clearance. If your truck is equipped with four wheel drive, you’re probably in the market for an all-terrain or mud terrain tire that offers great traction off the pavement with an aggressive tread pattern and a reinforced casing that can hold up under rough off-road use.