🔗 Share this article

PHEVs produce almost 5x more planet-heating pollution than official data show, according to a new analysis.

Growing Gap Between Lab and Actual Emissions

Statistics reveals that PHEVs emit just one-fifth lower CO₂ than conventional petrol and diesel cars, based on research conducted by a advocacy group. This contrasts sharply with laboratory estimates, which suggested a 75% reduction in pollution.

Analysts studied data from onboard fuel consumption monitors of 800,000 cars registered in the EU between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official estimates, increased from 3.5 times in 2021.

“Real-world emissions are increasing, while official figures are decreasing,” stated a senior analyst involved in the study. “This gap is growing and poses a serious problem. As a result, PHEVs emit nearly as heavily as petrol cars.”

Key Reasons Driving the Discrepancy

Analysts attributed most of the gap to overestimates of the “electric driving share” – the percentage of miles travelled in electric mode compared to total distance. The team determined that just a quarter of travel was done in electric mode, while lab assumptions suggested over four-fifths.

Even, when running in EV mode, emission amounts were significantly higher than lab projections. That occurred because electric motors were not strong enough to operate independently, leading to engines using fossil fuels for nearly a third of the distance completed in EV mode.

Regulatory and Financial Consequences

According to calculations, the lowballing of PHEV emissions allowed four large automaker groups to avoid over €5bn in fines between 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO₂ standards.

Additionally, owners of PHEVs would pay approximately €500 extra annually in running costs than is estimated under laboratory tests.

“The bold statements that manufacturers often promote about their PHEV vehicles are clearly far from the truth,” stated a automotive expert. “Consumers are being misled into believing that by buying a PHEV, they are benefiting the planet and saving costs. In reality, PHEVs are only slightly better than regular gas and diesel vehicles in terms of energy consumption, CO₂ emissions, and operating expenses.”

Political Debate and Automotive Lobbying

Plug-in hybrid cars have recently been drawn back into political debates as automakers have lobbied the EU to weaken CO₂ standards. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense pressure from the car industry and opposition from member states with significant automotive manufacturing.

Some senior officials have proposed PHEVs as a possible “flexibility” solution to include in the regulation.

One independent energy economics expert, who was unaffiliated with the research, described the report a “highly valuable addition” after a long period in which segments of the automotive industry claimed there was insufficient information to properly assess real-world CO2 output.

“The results show, without question, that the gap between official and actual PHEV fuel consumption and CO₂ emissions is much, much greater than for petrol or diesel cars,” the expert stated. “Any regulatory changes regarding PHEVs should be implemented with extreme care and considering this evidence.”