Get detailed information on the best GMC gas mileage trucks and SUVs with over 20 MPG and do side-by-side comparisons to help you with your new car buying. Research 20 - 30 MPG GMC trucks and fuel efficient 2014 2013 new SUVs with high MPG including EPA fuel economy ratings, miles per gallon, car prices, cost of ownership, safety, recalls, standard features, options, warranty, fuel economy, specifications, and more on any new 20 - 30 MPG GMC truck models. Click on the links below to find the right vehicle for you!