The automotive industry has made a substantial effort in recent years to develop powertrain technologies to improve the fuel efficiency of Heavy-Duty Vehicles (HDVs). However, due to increasing road freight traffic, projections indicate that total HDV energy use and CO2 emissions are expected to remain stable at the current level over the long term, if no policy action is taken. This is clearly incompatible with the goal of reducing greenhouse gas emissions from transport by around 60% below 1990 levels by 2050.