The fuel economy of the Acura MDX and RDX models vary by model year and type of driving. The 2015 models, which both feature a 3,471 cubic centimeter, 3.5 liter V6 engine, get 20 miles per gallon in the city and 28 miles per gallon on the highway.
The MDX model features a maximum 290 horsepower at 6,200 revolutions per minute. The RDX provides 273 horsepower at the same frequency of rotation. Additionally, the MDX is a larger vehicle with 68.4 cubic feet of storage space and the ability to seat seven people; in contrast, the RDX has approximately 61 cubic feet of cargo room and only seats five.