Fuel economy analysis of conventional and hybrid heavy vehicle combinations over real-world operating routes

•The impacts of higher weights and hybridization on fuel economy of heavy vehicle combinations were evaluated.•The specific fuel consumption can be significantly reduced with higher payload capacities.•The fuel economy can be improved up to 6% by hybridization.•The amount of hill climbing has a major impact on fuel economy.

This research evaluates the fuel economy of conventional and hybrid heavy vehicle combinations. The evaluation takes into account four heavy vehicle combinations with different total weights and three parallel hybrid configurations, which were developed for the tractor powertrain. The simulation models of conventional diesel powered and parallel hybrid vehicle combinations were developed in the Autonomie vehicle simulation software. Simulations were carried out in real-world operating routes that had been measured from popular truck routes in southern Finland. According to the simulations results, for one ton of additional weight to the total weight of the vehicle combination, the fuel consumption increases by 0.65–0.95 l/100 km depending on the operating route. The payload specific fuel consumption (the amount of fuel consumed per payload ton-kilometer) decreases on average 17% when total combination weight increases from 40 t to 60 t. The decrease is 23% when going from 40 t to 76 t and 28% when going from 40 t to 90 t. According to the simulation results, the fuel economy of a heavy vehicle combination can be improved by up to 6% by hybridization. The simulation results also indicate that the hybridization is more beneficial in operating routes which have more hill climbing.