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 modifications, model year, horsepower, and fuel economy. First of all, the 2016 XJ XJR has a more powerful engine than the 2014 S8, and it gets 1 fewer mile on a gallon of fuel. Among similarities are the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy.