Fuel consumption and CO2 emissions of plug-in hybrid vehicles in real-world driving conditions
Plug-in-Hybride haben einen viel höheren Verbrauch als bisher angenommen.
© plainpicture/Cavan Images
Plug-in hybrid electric vehicles (PHEVs) can run on electricity or a combustion engine, but only offer climate benefits when running on electricity.
Current evaluations of around one million PHEVs from 2021–2023 show that their actual fuel consumption and thus their real CO₂ emissions are on average three to five times higher than the officially stated values. Real fuel consumption averages 5.9 l/100 km, which is close to the average for combustion engines (approx. 7 l/100 km). The main reason for this is that PHEVs only cover about 25–30% of their kilometres electrically on average.
The huge gap between official and actual fuel consumption massively weakens the effectiveness of European CO₂ regulations.
A key regulatory issue here is the so-called utility factor (UF), which is intended to calculate the estimated proportion of electric driving for the EU fleet targets. It determines how much driving with a charged battery and driving with an empty battery are included in the official combined consumption value of a vehicle. The analysis shows two things: firstly, the proportion of operation with a charged battery in relation to the total distance travelled has been assumed too optimistically up to now. Secondly, even with a charged battery, far less electric driving is done than expected: across the entire fleet, fuel consumption of almost 3 litres per 100 km was still observed for the ‘predominantly electric operating mode’.
The adjustments to the UF already provided for by law until 2028 cannot close the gap between real and standard consumption, but they can at least reduce it significantly. Nevertheless, some stakeholders are now calling for these adjustments to be suspended. However, this would significantly weaken European CO2 regulations for passenger cars and lead to additional emissions in the transport sector of up to 25 million tonnes of CO2 in Germany alone. In order to reduce the gap between actual consumption and official values to a level similar to that currently seen for combustion engine cars, it would be necessary to further tighten the UF for PHEVs.
Policy Brief “Regulatory adjustments needed for plug-in hybrid vehicles in Europe”
Study “Regulatory adjustments for plug-in hybrid vehicles in Europe”
