(Phys.org)—As fuel economy of new vehicles improved 18 percent over the past five years, billions of gallons of gas and billions of pounds of emissions have been saved, University of Michigan researchers say.
For the past several years, the average was calculated (on a monthly basis), salesweighted 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 2012, the average fuel economy has improved by 18%, from 20.1 mpg to 23.8 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 6.1 billion gallons of fuel—equivalent to the current total consumption of all vehicles in the U.S. for about 13 days. This reduction in the amount of fuel translates to a reduction of about 120 billion pounds of carbon-dioxide emissions. In terms of the current savings, for the most recent month—September 2012— the savings amount to 293 million gallons of fuel, or about 5.7 billion pounds of carbon dioxide. These savings are equivalent to about 2.9% of the average monthly consumption of fuel and of carbon-dioxide emissions from all light-duty vehicles on the road. (An axcerpt from an article by Sivak, Michael published by University of Michigan, Ann Arbor, Transportation Research Institute).
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.”
More information: deepblue.lib.umich.edu/handle/2027.42/93781
Provided by University of Michigan
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- New vehicle emissions show record improvement (ns.umich.edu)