What we have here are two Coupes from Audi with some differences, such as the starting price, horsepower, and fuel economy. First of all, there is a $17,800 difference in the base MSRP. The 2015 Audi RS 5 Coupe has a higher starting price than the 2016 Audi S5 Coupe. And finally, the 2015 RS 5 Coupe has a more powerful engine and gets 2.5 mpg less than the 2016 S5 Coupe. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.