Two Sedans with more similarities, such as the body structure, market segment, ground shadow size, height, and maximum occupancy, than differences, like the powertrain, market segment, starting price, horsepower, and fuel economy. First of all, a bigger engine usually means less mpg. But the 2016 INFINITI Q70 Hybrid has a more powerful engine and it gets 7 more mpg than the 2015 Acura RLX. Also, the 2015 RLX is priced $7,450 lower compared to the base MSRP of the 2016 INFINITI Q70 Hybrid. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.