Two Sedans with some similarities, but otherwise different in most aspects such as the powertrain, horsepower, model year, starting price, fuel economy, and maximum occupancy. First of all, the 2016 Audi A6 is priced $5,200 lower compared to the base MSRP of the 2014 Mercedes-Benz E-Class Sedan Diesel, which is older by two model years. Also, the 2016 A6 has a more powerful engine than the 2014 E-Class Sedan Diesel, and it gets 6.4 fewer miles on a gallon of fuel. In addition, you'll seat two more passengers in the E-Class Sedan Diesel than in the A6. Among similarities are the body structure, market segment, ground shadow size, and height.