Transformational Trucks: Determining the Energy Efficiency Limits of a Class-8 Tractor Trailer
Rocky Mountain Institute: White Paper
Feasible technological improvements in vehicle ef?ciency, combined with “long combination vehicles” (which raise productivity by connecting multiple trailers), can potentially raise the ton-mile ef?ciency of long-haul heavy tractor-trailers by a factor ~2.5 with respect to a baseline of 130 ton-miles/gal. Within existing technological and logistical constraints, these innovations (which do not include such further opportunities as hybrid-electric powertrains or auxiliary power units to displace idling) could thus cut the average fuel used to move each ton of freight by ~64 percent. This would annually save the current U.S. Class 8 ?eet about four billion gallons of diesel fuel and 45 million tonnes of carbon dioxide emissions. Further bene?ts would include lower shipping costs, bigger pro?ts for trucking companies, fewer tractor-trailers on the road, and fewer fatal accidents involving them. Thus transformational, not incremental, redesign of tractors, trailers, and (especially) both as in integrated system can broadly bene?t economic prosperity, public health, energy security, and environmental quality.