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 model year, horsepower, and fuel economy. First of all, the 2016 K900 has bigger and thirstier engine; the 2014 XTS gets 1 more mpg. Among similarities are the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy.