Two SUVs with more similarities, such as the body structure, market segment, ground shadow size, height, and maximum occupancy, than differences, like the starting price, horsepower, and fuel economy. First of all, the 2018 Acura RDX is priced $6,195 lower compared to the base MSRP of the 2018 Alfa Romeo Stelvio. And finally, the 2018 Stelvio has a more powerful engine than the 2018 RDX, but it gets 1.5 more miles on a gallon of fuel. Among similarities are the body structure, market segment, ground shadow size, height, and maximum occupancy.