Two Sedans with some similarities, but otherwise different in most aspects such as the powertrain, horsepower, market segment, starting price, and fuel economy. First of all, the 2016 Mercedes-Benz S-Class Sedan Hybrid has a more powerful engine than the 2015 Audi A8 Diesel, and it gets 2 fewer miles on a gallon of fuel. Also, the 2015 A8 Diesel is priced $10,550 lower compared to the base MSRP of the 2016 S-Class Sedan Hybrid. Among similarities are the body structure, market segment, ground shadow size, and height.