Two Coupes with some similarities, but otherwise different in most aspects such as the horsepower, fuel economy, ground shadow size, and maximum occupancy. First of all, a bigger engine usually means less mpg. But the 2016 BMW M4 GTS has a more powerful engine and it gets 3 more mpg than the 2016 Maserati GranTurismo. Also, the 2016 M4 GTS has a slightly smaller body than the 2016 GranTurismo. And finally, you'll seat two more passengers in the GranTurismo than in the M4 GTS. Among similarities are the body structure, market segment, starting price, and height.