Carbon dioxide emissions from plug-in hybrid (PHEV) cars are almost five times higher, on average, than official tests suggest, according to new data published by the EU.

Analysis of data from the European Environment Agency by T&E found that PHEVs emit an average of 139g of CO2 per km. That compares with the 28g per km in official tests.

PHEVs account for 8.6 per cent of EU car sales this year and some carmakers want to continue selling them even after the current 2035 deadline for zero-emission cars.

The real-world data was gathered from fuel monitors on 127,000 plug-in hybrid vehicles registered in 2023. It differs hugely from the tests where vehicles are driven in a way that is considered to be normal. The EU has set ‘utility factors’ to correct the CO2 rating. The utility factors set for 2025 and 2027 gradually tighten the gap, and will mean that carmakers will have to reduce their sales of PHEVs or increase their battery electric car sales in order to comply with EU CO2 targets.

Lucien Mathieu, cars director at T&E, said: “Plug-in hybrids are still worse for the climate than carmakers claim and the gap with reality has only gotten worse. The car industry is demanding that the EU turn a blind eye so it can delay investing in fully electric cars. The EU Commission must stand its ground and stick to the already agreed utility factors for 2025 and 2027.”

---