Two Convertibles with some similarities, but otherwise different in most aspects such as the starting price, horsepower, fuel economy, and height. First of all, the 2015 Audi RS 5 Convertible is priced $17,000 lower compared to the base MSRP of the 2016 Porsche 911 Convertible. Also, although the 2016 911 Convertible has a more powerful engine than the 2015 RS 5 Convertible, it gets 3 more mpg. And finally, the RS 5 Convertible is slightly taller than the 911 Convertible. Among similarities are the body structure, market segment, ground shadow size, and maximum occupancy.