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 notable difference in the starting price of the 2016 Maserati Quattroporte, which is $17,300 less than the base MSRP of the 2016 BMW M6 Gran Coupe. Also, the 2016 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.