3.8

Another size made popular by Traxxas, particularly with the E-revo. The big tires are (surprise) found on big 1/8 scale vehicles. Nearly all 3.8” wheels use 17mm hexes, because the larger hexes better resist stripping out when subjected to the heavy weight and greater power of 1/8 scale models.

Big trucks, big tires. Most 1/8 scale trucks wear 3.8” wheels.