Vehicle weight is retained as the underlying utility parameter, i.e., the heavier amanufacturer’s car fleet, the higher that manufacturer’s CO2 emission target will beunder the regulation.10 Until 2024, a factor of 0.0333 will be used, meaning that forevery 100 kilograms (kg) by which a manufacturer’s average vehicle weight exceedsthe average EU fleet mass, 3.33 g/km higher CO2 emissions will be allowed. Todetermine the slope applied for calculating annual manufacturer targets from 2025onwards, the European Commission will carry out a least-squares fit through the CO2vs. mass data of all vehicles registered in 2021.