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U.S. Department of Energy Energy Efficiency and Renewable Energy

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
Graph showing the percent improvement in fuel economy for Class 8 tractor trailers when various combinations of tires were used. For more detailed information, see the table below.

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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