Two Sedans with more similarities, such as the body structure, starting price, horsepower, ground shadow size, height, and maximum occupancy, than differences, like the model year and fuel economy. First of all, you get 2 more mpg with the 2014 Sonic Sedan than with the 2016 Rio Sedan. Among similarities are the body structure, starting price, horsepower, ground shadow size, height, and maximum occupancy.