Two Sedans with more similarities, such as the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy, than differences, like the powertrain, horsepower, and fuel economy. First of all, the 2015 Mercedes-Benz C-Class Sedan has bigger and thirstier engine; the 2016 BMW 3 Series Sedan Diesel gets 9.3 more mpg. Among similarities are the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy.