The University of Michigan Transportation Research Institute (UMTRI) keeps close tabs on what cars are sold in America and in what quantities. When they crunched the most recent numbers, the month of May, 2014 saw the highest average fuel economy ever – 25.6 mpg. The Institute also calculates Corporate Average Fuel Economy (CAFE), a sales weighted number, and found that too was the highest ever recorded at just over 31 mpg.
Those numbers are going up because manufacturers are bringing more models of fuel efficient cars to market – hybrids, plug-in hybrids and electric cars – and more people are buying them. Sales of the popular Toyota Prius are up 14% from a year ago, while Nissan just recorded more than 3000 sales of its Leaf model in a single month for the first time.
In all, average fuel economy in the United States is up over 20% in the past 5 years, though automakers still have a long ways to go to meet increasingly stringent efficiency mandates. Lawmakers have called for a CAFE average of 54.5 MPG by 2025, which has automakers embracing lightweight materials like carbon fiber and small-displacement, turbocharged engines.