Plug-in hybrids emit far more CO2 than official data suggest study shows

Plug-in hybrid vehicles (PHEVs) emit nearly five times more carbon dioxide in real-world driving than official tests show, according to the Guardian, citing a study by Transport & Environment (T&E).

The report draws on data from 800,000 vehicles across Europe between 2021 and 2023. It finds that PHEVs produce only 19% less CO2 than petrol or diesel cars, even though they have been widely promoted as a lower-emission alternative to regular vehicles. For example, under lab conditions, testers assumed the cars emitted 75% less.

Researchers identify the main reason for the difference is that drivers use electric mode much less than expected — about 27% of the time, compared with the official estimate of 84%. Also, even in electric mode, many vehicles still rely on their combustion engines for part of the trip, because the electric motor alone often does not provide enough power for confident driving.

T&E states that the findings reveal a growing gap between real-world and official emissions data, allowing carmakers to avoid billions of euros in EU fines between 2021 and 2023. The European Commission has already announced steps to revise its emissions testing model, but analysts argue that the adjustments will not fully resolve the gap, the Guardian reported.

Meanwhile, some European automakers urge the EU to embrace a broader approach to the green transition, as rapid actions could damage the automotive industry, which is already struggling with shrinking sales, rising energy costs, and fierce international rivals.