Two Sedans with more similarities, such as the body structure, market segment, starting price, ground shadow size, and height, than differences, like the modifications, model year, horsepower, fuel economy, and maximum occupancy. First of all, the 2016 M5 has a more powerful engine and gets 2 mpg less than the 2014 CLS-Class CLS63 AMG 4MATIC. Also, you'll seat one more passenger in the M5 than in the CLS-Class CLS63 AMG 4MATIC. Among similarities are the body structure, market segment, starting price, ground shadow size, and height.