Two SUVs with more similarities, such as the body structure, market segment, starting price, height, and maximum occupancy, than differences, like the horsepower, fuel economy, and ground shadow size. First of all, the 2016 Cadillac SRX has bigger and thirstier engine; the 2015 Acura RDX gets 4 more mpg. And finally, the body structure of 2015 RDX is slightly smaller than that of the 2016 SRX. Among similarities are the body structure, market segment, starting price, height, and maximum occupancy.