Two Pickups with some similarities, but otherwise different in most aspects such as the model year, horsepower, starting price, ground shadow size, and height. First of all, there is a notable difference in the starting price of the 2013 GMC Sierra 1500 Extended Cab, which is $5,340 less than the base MSRP of the 2016 Chevrolet Silverado 2500HD Regular Cab, which is three model years newer. Also, the 2016 Silverado 2500HD Regular Cab pulls more horsepower than the 2013 Sierra 1500 Extended Cab. And finally, although the Silverado 2500HD Regular Cab is slightly smaller, it has a taller body than the Sierra 1500 Extended Cab. Among similarities are the body structure and maximum occupancy.