Two Convertibles with some similarities, but otherwise different in most aspects such as the starting price, horsepower, ground shadow size, and height. First of all, the 2015 BMW 6 Series Convertible is priced $12,600 lower compared to the base MSRP of the 2016 Porsche 911 Convertible. Also, the 2015 6 Series Convertible produces fewer horsepower than the 2016 911 Convertible. And finally, the 6 Series Convertible body is slightly larger than the 911 Convertible, and in addition to that, it's also taller. Among similarities are the body structure, market segment, fuel economy, and maximum occupancy.