Two Sedans with some similarities, but otherwise different in most aspects such as the starting price, horsepower, ground shadow size, fuel economy, and height. First of all, there is a notable difference in the starting price of the 2015 Cadillac ATS, which is $15,785 less than the base MSRP of the 2016 Kia K900. Also, the 2016 K900 has a more powerful engine than the 2015 ATS, and it gets 4 fewer miles on a gallon of fuel. And finally, not only ATS is significantly smaller, but it's also slightly shorter than the K900. Among similarities are the body structure, market segment, and maximum occupancy.