Two Sedans with more similarities, such as the body structure, ground shadow size, height, and maximum occupancy, than differences, like the modifications, market segment, starting price, horsepower, and fuel economy. First of all, there is a notable difference in the starting price of the 2016 Cadillac ATS, which is $4,180 less than the base MSRP of the 2015 Subaru WRX STI Launch Edition. Also, the 2015 WRX STI Launch Edition has bigger and thirstier engine; the 2016 ATS gets 5.2 more mpg. Among similarities are the body structure, ground shadow size, height, and maximum occupancy.