Tires play a critical role in the operation of any vehicle. Trucking fleets have opportunities to reduce fuel consumption and emissions through tire maintenance (such as proper tire alignment and pressure) and choice of tires. Of particular interest are the latest generations of low rolling resistance tires, single wide-base tires, and nitrogen-filled tires.
For a summary of recent research from FPInnovations, see Wide-Base and Low Rolling Resistance Tires, hosted on the Transport Canada website.
Low Rolling Resistance Tires
Manufacturers claim at least 4% savings in fuel costs in switching from conventional tires to low rolling resistance tires. FPInnovations conducted fuel consumption tests that showed up to 2.4% improvement in fuel economy for tractor-trailers that were equipped with one brand of these tires on the drive axles only.
Single Wide-Base Tires
Traditionally, combination trucks have had dual tire assemblies on the drive and trailer axles, with two sets of wheels and tires at each end of an axle. An alternative, endorsed by the US EPA and BC Trucking Association is use of single wide-base tires, often called “super singles.”
A single wide-base tire and wheel is lighter than two standard tires and wheels and costs less. Total weight savings for a typical combination truck using single wide-base tires on its drive and trailer axles ranges from 800 to 1,000 pounds. The weight savings reduce fuel consumption, or increase cargo carrying capacity for trucks that are weight-limited. Wide-base tires also have lower rolling resistance and aerodynamic drag, further enhancing fuel mileage.
Using one tire also increases a truck’s stability as the clearance between the wheel centers increases. Additionally, fleets can achieve cost savings through reduced tire repairs and lower recycling fees.
FPInnovations reported that a truck equipped with single, wide-base radial tires travelling at a constant speed of 100 km/h would reduce fuel consumption by 9.7% compared with a truck equipped with conventional dual tires. Because trucks do not operate 100% of the time at full highway speeds, the study concluded that results during operations would be lower. FPInnovations determined that the use of single wide-base tires on two 8-axle B-train tractor-trailer combinations would mean an average 5.11% fuel improvement.
Weight regulations for single wide-base tires vary province to province. A chart is set out in the FP Innovations summary. Check with BC Ministry of Transportation and Infrastructure for current requirements in British Columbia.
Filling tires with nitrogen rather than air presents another opportunity for a 4-6% fuel savings and longer tread life, according to a 2006 study by Drexan Corporation.