Two Convertibles with some similarities, but otherwise different in most aspects such as the horsepower, ground shadow size, height, and maximum occupancy. First of all, the 2015 Audi A5 Convertible produces fewer horsepower than the 2016 Porsche Boxster. Also, not only 2015 A5 Convertible is slightly larger, but it's also taller than the 2016 Boxster. And finally, the A5 Convertible seats two more passengers than the Boxster. Among similarities are the body structure, market segment, starting price, and fuel economy.