Two Pickups with more similarities, such as the body structure, starting price, height, and maximum occupancy, than differences, like the horsepower and ground shadow size. First of all, the 2018 GMC Sierra 2500HD Crew Cab pulls more horsepower than the 2018 Toyota Tundra CrewMax Cab. And finally, the body structure of 2018 Sierra 2500HD Crew Cab is slightly larger than that of the 2018 Tundra CrewMax Cab. Among similarities are the body structure, starting price, height, and maximum occupancy.