Two Pickups with more similarities, such as the body structure, starting price, ground shadow size, height, and maximum occupancy, than differences, like the horsepower and fuel economy. And finally, the 2018 Toyota Tundra CrewMax Cab has a more powerful engine and gets 3.5 mpg less than the 2018 GMC Sierra 1500 Crew Cab. Among similarities are the body structure, starting price, ground shadow size, height, and maximum occupancy.