The University of Michigan’s Transportation Research Institute released an analysis October 8 finding that average fuel economy for light-duty vehicles increased 18 percent between October 2007 and September 2012. The report, Benefits of Recent Improvements in Fuel Economy on Overall Fuel Consumption and Emissions, concluded that tougher fuel economy requirements saved 6.1 billion gallons of fuel and prevented 120 billion pounds of CO2 emissions over five years.