Two Convertibles with more similarities, such as the body structure, market segment, ground shadow size, height, and maximum occupancy, than differences, like the modifications, starting price, horsepower, and fuel economy. First of all, the 2016 BMW M6 Convertible is priced $62,309 lower compared to the base MSRP of the 2015 Maserati GranTurismo Convertible MC Centennial. Also, the 2016 M6 Convertible has a more powerful engine than the 2015 GranTurismo Convertible MC Centennial, but it gets 1 more mile on a gallon of fuel. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.