A list of the most fuel efficient SUV's of 2012-2013. Both Large and mid-sized SUV's have been included. Each SUV on this list has an overall mpg of at least 18mpg. Sport utility vehicles were a staple of the 90's, but with fuel costs reaching all time highs, even the largest cars on the road have needed to go green. Fortunately, with the latest technology the automotive industry has to offer, these mid-sized and large SUVs come with the acceleration of a powerful engine, the utility of a normal SUV and the fuel economy of a small car.