Two Coupes with more similarities, such as the body structure, market segment, starting price, ground shadow size, and maximum occupancy, than differences, like the fuel economy, market segment, horsepower, and height. First of all, the 2017 Maserati GranTurismo has a more powerful engine and gets 12 mpg less than the 2017 BMW i8. Also, the 2017 i8 has a slightly taller body than the 2017 GranTurismo. Among similarities are the body structure, market segment, starting price, ground shadow size, and maximum occupancy.