Benefits of recent improvements in vehicle fuel economy

For the past several years, we have calculated (on a monthly basis) the average, sales-weighted fuel economy of all light-duty vehicles (cars, pickup trucks, vans, and SUVs) sold in the U.S. The results indicate that, from October 2007 to September 2014, the average fuel economy has improved from 20.1 mpg to 25.3 mpg. This brief note quantifies the consequences of this improvement on overall fuel consumption and vehicle emissions. Because of their improved fuel economy, the vehicles sold since October 2007 saved a cumulative total of about 15.1 billion gallons of fuel—equivalent to the current total consumption of all vehicles in the U.S. for about 33 days. This reduction in the amount of fuel translates to a reduction of about 297 billion pounds of carbon-dioxide emissions. In terms of the current savings, for the most recent month—September 2014—the savings amount to 614 million gallons of fuel, or about 12 billion pounds of carbon dioxide. These savings are equivalent to about 6% of both the average monthly fuel consumption and carbon-dioxide emissions from all light-duty vehicles on the road.The University of Michigan Sustainable Worldwide Transportationhttp://deepblue.lib.umich.edu/bitstream/2027.42/109199/1/103026.pd