U.S. Department of Energy - Energy Efficiency and Renewable Energy
Vehicle Technologies Program
Fact #537: September 22, 2008
Replacing Dual Tires with Single Wide Tires on Class 8 Tractor Trailers Improves Fuel Economy
A year-long nationwide highway test of six instrumented Class 8 tractor-trailers hauling freight over three quarters of a million miles was conducted in 2007. The study concluded that fuel efficiency improved by using a single wide tire instead of the dual tires traditionally found on tractor trailers. Trucks with both the tractor and trailer fully equipped with single wide tires achieved a fuel economy of 7.35 miles per gallon while traditionally equipped dual tire tractor-trailers achieved 6.73 miles per gallon. This equates to a 9.2% improvement in fuel economy for a truck fully equipped with single wide tires.
Improvements in Fuel Economy with Various Combinations of Tires on Class 8 Tractor Trailers 
Supporting Information
Fuel Economy of Class 8 Trucks as Function of Tractor-Trailer Tire Combination
| Tire Combinations |
Fuel Economy (miles per gallon) |
Percentage Improvement |
| Dual Tire Tractor / Dual Tire Trailer |
6.7 |
0.0 |
| Dual Tire Tractor / Single (Wide) Tire Trailer |
7.1 |
5.9 |
| Single (Wide) Tire Tractor / Dual Tire Trailer |
7.2 |
6.5 |
| Single (Wide) Tire Tractor / Single (Wide) Tire Trailer |
7.4 |
9.2 |
|
Source: Oak Ridge National Laboratory, Transportation Energy Data Book: Edition 27. Table 5.10 "Fuel Economy for Class 8 Trucks as Function of Speed and Tractor-Trailer Combination." |
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