Michael Sivak and Brandon Schoettle of the U-M Transportation Research Institute collected fuel data on 61 million new cars, pickup trucks, minivans and SUVs sold in the U.S. since 2007—about a quarter of all light vehicles, both new and used, on U.S. roads today.
Using a recent estimate of the average annual distance driven in the U.S. (about 13,000 miles every year), the researchers found that new vehicles in the last five years saved about 6.1 billion gallons of fuel—equal to about two weeks' worth of gas consumption for all vehicles in the U.S.
They also looked at the current monthly savings in fuel use for new vehicles and found that 293 million gallons of fuel were saved in September alone.
"The reductions in the amount of fuel consumed are important in themselves," said Sivak, a research professor at UMTRI. "However, they also represent reductions in emissions."
Sivak and Schoettle say that since late 2007, carbon dioxide emissions have been reduced by about 120 billion pounds. During September, the reduction was 5.7 billion pounds—about 3 percent of the average monthly consumption of fuel and of carbon dioxide emissions of all light vehicles on the road today.
"The improvements in vehicle fuel economy over the past five years are noteworthy, especially in relation to the improvements during the preceding eight decades," Sivak said. "As a consequence, we have seen sizeable savings in fuel consumed and emissions produced. The new fuel economy standards issued in August will accelerate this process."