What we have here are two Convertibles from Audi with some differences, such as the horsepower, starting price, and fuel economy. First of all, the 2016 Audi S5 Convertible is priced $18,100 lower compared to the base MSRP of the 2015 Audi RS 5 Convertible. And finally, the 2015 RS 5 Convertible has a more powerful engine than the 2016 S5 Convertible, and it gets 3 fewer miles on a gallon of fuel. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.