Two Sedans 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 2017 Audi S8 is priced $29,600 lower compared to the base MSRP of the 2017 Maserati Quattroporte GTS GranLusso. Also, a bigger engine usually means less mpg. But the 2017 S8 has a more powerful engine and it gets 1 more mpg than the 2017 Quattroporte GTS GranLusso. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.