Two Convertibles with some similarities, but otherwise different in most aspects such as the modifications, fuel economy, horsepower, and height. First of all, the 2017 Bentley Continental Convertible GT Speed has a more powerful engine and gets 5 mpg less than the 2018 Aston Martin DB11 Volante. Also, the 2018 DB11 Volante has a slightly taller body than the 2017 Continental Convertible GT Speed. Among similarities are the body structure, market segment, ground shadow size, and maximum occupancy.