According to the EPA SmartWay Partnership program data, tire rolling resistance accounts for nearly 13% of truck energy use. Most combination trucks have dual tire assemblies on the drive and trailer axles, with two sets of wheels and tires at each end of an axle. This configuration increases rolling resistance and weight, compared to single wide-base tires and wheels.
Widebase tires have lower rolling resistance and aerodynamic drag, and generate slightly less pass-by noise than do dual tires. The new generation of widebase tires has a section width of up to 17.5 in., so these tires comply with pavement weight laws in all 50 states, for a typical tandem axle combination truck.
Wide-base tires can improve the stability of tank trailers by allowing the tank to be mounted lower. In a test of 15 fleets driving 57 million miles using its latest wide-base tire models, one manufacturer reported that the tires wear at a rate comparable to conventional tires. Wide-base tires also can be retreaded.
Recent tests of wide-base tires indicate a potential fuel economy improvement of 2% to 5% compared to equivalent dual tires. By using wide-base tires, a combination long-haul truck could save over 400 gallons of fuel per year and cut emissions of carbon dioxide (the most common greenhouse gas) by more than four metric tons annually. Most importantly, these environmental benefits can often be achieved while cutting costs. A single widebase tire costs about the same as two equivalent dual tires and a single wide-rim wheel typically costs about $130 less than two standard wheels. Retrofitting existing trucks with wide-base tires and wheels may not be cost effective. However, for new trucks, the “payback” is instantaneous, since the initial savings could exceed $1,000. In addition, fuel savings begin immediately.
Wheel savings
Wheel manufacturers are offering aluminum wheels in 22.5×14-in. sizes to help bring additional weight and fuel savings to fleets. Alcoa notes that some fleets have experienced savings of 3% to 7% with wide-base wheel and tire combinations. Estimates from Accuride include 2.5 % fuel savings per tractor and 5% per combination vehicle.
Actual weight savings with widebase aluminum wheels vary by manufacturer. Alcoa’s 14-in. wide base aluminum wheels, according to the company, can save 318 lbs. per axle or 1,272 lbs. per combination when used in place of dual wheels on drive and trailer positions. The wheels, which weigh only 68 lbs. each, are load rated up to 12,800 lbs. Alcoa’s current LvL ONE 14-in. wheel weighs just 62 lbs. As reference, the equivalent steel 14-in. widebase wheel weighs 127 lbs. Steel single wheels weigh about (depending upon manufacturer) 68 lbs. each. That’s 136 lbs. for the two to be replaced by one Alcoa 14-in. wide base at 62 lbs.
The company also notes that fleets can save 1,350 lbs. by outfitting a tractor-trailer with its 14-in. widebase wheels and tires (total: 2,250 lbs.) rather than steel single wheels and tires (total: 3,600). So, a 1,350 lb. weight savings on tractor-trailer increases load capacity or increases fuel savings by 3-5%. In addition, Alcoa aluminum wheels provide a better appearance and lower maintenance costs through reduced upkeep (no paint, retouch, etc.) and higher resale value.
Accuride’s DupleX-One wide-base 22.5×14-in. aluminum wheels, the company notes, reduce fuel expense or increase payload capacity when used in place of traditional dual wheel sets on tandem-axle tractors and trailers. Developed in conjunction with Michelin, the forged aluminum wheels can save 120 lbs. per axle.
Webb Wheel Products said it has designed Vortex drums to meet the demand for a lighter weight grey iron drum with better performance features and a lower cost than current lightweight drums available for heavy trucks and trailers. There is a thermal advantage since the company said its Vortex drum runs cooler and dissipates heat faster than steel-shelled lightweight brake drums. There is also a weight advantage: 12 lbs. per wheel end advantage over standard grey iron drums. In addition, the Vortex drums run cooler than and exceed all FMVSS121 requirements for brake torque, brake power and brake recovery, the company added.
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Alcoa widebase aluminum wheel
