Two Sedans with some similarities, but otherwise different in most aspects such as the powertrain, starting price, horsepower, fuel economy, market segment, and maximum occupancy. First of all, the 2017 Audi RS 7 has a more powerful engine than the 2017 Acura RLX Hybrid, and it gets 11 fewer miles on a gallon of fuel. Also, there is a $50,750 difference in the base MSRP. The 2017 RS 7 has a higher starting price than the 2017 RLX Hybrid. In addition, you'll seat one more passenger in the RLX Hybrid than in the RS 7. Among similarities are the body structure, market segment, ground shadow size, and height.