Losses due to rolling resistance are higher for heavier vehicles than for autos. In a Class 8 tractor trailer at 65 mph, 13% of fuel is lost to rolling resistance. More efficient wide base single (WBS) tires do the work of dual tires with the same performance and safety but less weight (by 200 lb/axle, including switching from steel to aluminum rims).
Currently, 5–10% of heavy trucks use WBS tires; an additional 60% specify a low rolling resistance tire.
Low rolling resistance dual tires provide a 2–3% fuel consumption benefit while cutting edge next-generation WBS tires provide 11–13% fuel economy improvements.
Bockholt, Wendy, and Matthew Kromer. 2009. Assessment of Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles. TIAX LLC.