Two Sedans with some similarities, but otherwise different in most aspects such as the modifications, model year, starting price, horsepower, fuel economy, and height. First of all, the 2016 BMW M6 Gran Coupe is priced $22,300 lower compared to the base MSRP of the 2014 Mercedes-Benz S-Class S63 AMG 4MATIC, which is older by two model years. Also, the 2014 S-Class S63 AMG 4MATIC has a more powerful engine than the 2016 M6 Gran Coupe, but it gets 2 more miles on a gallon of fuel. In addition, the roofline of the M6 Gran Coupe is slightly lower than the S-Class S63 AMG 4MATIC's. Among similarities are the body structure, market segment, ground shadow size, and maximum occupancy.