2018 Ram 1500 Crew Cab is the newer version with some differences, such as the horsepower and fuel economy.. And finally, the 2018 Ram 1500 Crew Cab has a more powerful engine than the 2018 Ram 1500 Quad Cab, and it gets 2 fewer miles on a gallon of fuel. Among similarities are the body structure, starting price, ground shadow size, height, and maximum occupancy.