Two Convertibles with more similarities, such as the body structure, market segment, height, and maximum occupancy, than differences, like the starting price, horsepower, fuel economy, and ground shadow size. First of all, there is a $95,440 difference in the base MSRP. The 2017 Maserati GranTurismo Convertible has a higher starting price than the 2017 BMW 4 Series Convertible. Also, the 2017 GranTurismo Convertible has a more powerful engine than the 2017 4 Series Convertible, and it gets 10.6 fewer miles on a gallon of fuel. And finally, the body structure of 4 Series Convertible is slightly smaller than that of the GranTurismo Convertible. Among similarities are the body structure, market segment, height, and maximum occupancy.