Two Sedans with some similarities, but otherwise different in most aspects such as the horsepower, starting price, fuel economy, ground shadow size, and height. First of all, there is a $15,800 difference in the base MSRP. The 2015 BMW M6 Gran Coupe has a higher starting price than the 2016 Maserati Quattroporte. Also, the 2015 M6 Gran Coupe has a more powerful engine and gets 2 mpg less than the 2016 Quattroporte. And finally, not only M6 Gran Coupe is slightly smaller, but it's also shorter than the Quattroporte. Among similarities are the body structure, market segment, and maximum occupancy.