When the European Union (EU) introduced its first set of mandatory new vehicle CO2 standards in 2009, for passenger cars, and 2011, for light commercial vehicles, vehicle mass was chosen as a utility parameter. Using mass as the normalizing parameter allows heavier vehicles to emit more CO2 and consume more fuel than lighter vehicles. As a result, the current EU CO2 target system offers little incentive to reduce the mass of vehicles: the lighter a manufacturer’s fleet, the lower its assigned CO2 target. If a manufacturer reduces the mass of its vehicles, it must then also achieve a lower g/km target. This eliminates most of the manufacturer’s weight reduction advantage and puts mass reduction at a competitive disadvantage compared to other CO2 saving technologies.
The situation is very different in a target system that is based on vehicle size instead. Here the manufacturer’s CO2 target does not change if mass reduction is applied and the manufacturer benefits fully from the CO2 reduction effect of lightweighting. In the United States, vehicle footprint is used as the utility parameter for both passenger cars and light trucks.
Because a weight-based CO2 target system discourages the use of lightweighting, it takes away flexibility from vehicle manufacturers and thereby increases the cost for regulatory compliance. A recent ICCT study finds that for cars, the cost for meeting a 2025 target value of 70 g/km (as measured in the New European Driving Cycle - NEDC) is between 250 and 500 euros higher than would be the case in a footprint-based CO2 target system. For light commercial vehicles, the cost for meeting a 2025 target value of 110 g/km is between 400 and 1,850 euros higher than if switching to a footprint based target system.