U.S. Department of Energy - Energy Efficiency and Renewable Energy
Vehicle Technologies Program
Fact #122: April 3, 2000
Potential Fuel Savings of Doubling Fuel Economy
The average large car sold in 1998 had a tested fuel economy of 26.9 miles per gallon (mpg). However, drivers generally achieve a lower efficiency than tested. Assuming a 15.2% fuel economy "gap" and the car is driven 130,000 miles before it is scrapped, doubling the fuel economy would save 2,849 gallons of the life of the vehicle. Tripling the fuel economy would increase the savings by 33% to 3,801 gallons. Doubling the fuel economy of the average light truck, which tested at 20.3 in 1998, would achieve greater fuel savings per vehicle than tripling the large car efficiency. Light trucks are driven more each year, are kept on-road longer, and have a larger "gap." Assuming a total of 140,000 miles and a 24.5% fuel economy gap, doubling the truck fuel economy would save 4,567 gallons over its lifetime. Doubling the fuel economy of large sport utility vehicles would yield the greatest benefit at 5,094 gallons per vehicle.
Assumptions:
- Large car: Lifetime mileage 130,000 miles. On-road fuel economy is 15.2% lower than tested (the fuel economy "gap").
- Light truck and large SUV: Lifetime mileage 140,000 miles. On-road fuel economy gap 24.5%.
Supporting Information
| Efficiency Improvement Factor |
Lifetime Fuel Savings (gallons) |
Large Car
(26.9 mpg) |
Large SUV
(18.2 mpg) |
Light Truck
(20.3 mpg) |
| 2X |
2,849 |
5,094 |
4,567 |
| 3X |
3,801 |
6,796 |
6,093 |
|
Sources: Philip D. Patterson, U.S. Department of Energy Office of Transportation Technologies, Quarterly Analytic Program Review, March 22, 2000.
EPA tested fuel economy from S. Davis, Transportation Energy Databook Edition 19, Oak Ridge National Laboratory, September 1999.
On-road fuel economy gap from J. Maples, University of Tennessee, The Light Duty Vehicle MPG Gap, SAE Government Industry Meeting, May 1993. |
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