Two Coupes with more similarities, such as the body structure, market segment, starting price, and maximum occupancy, than differences, like the modifications, horsepower, fuel economy, ground shadow size, and height. First of all, a bigger engine usually means less mpg. But the 2016 Porsche 911 Coupe GT3 RS has a more powerful engine and it gets 1 more mpg than the 2016 Maserati GranTurismo MC Centennial. Also, the 2016 GranTurismo MC Centennial body is slightly larger than the 2016 911 Coupe GT3 RS, and in addition to that, it's also taller. Among similarities are the body structure, market segment, starting price, and maximum occupancy.