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, modifications, horsepower, and fuel economy. First of all, the 2016 Cadillac CTS V-Sport has bigger and thirstier engine; the 2015 Audi A6 Diesel gets 10 more mpg. Among similarities are the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy.