🔗 Share this article

PHEVs emit almost five times greater planet-heating emissions than lab-reported figures show, as per a new analysis.

Widening Gap Between Official and Actual Emissions

Statistics reveals that PHEVs emit only 19% lower CO₂ than conventional gas and diesel vehicles, according to research conducted by a advocacy group. That contrasts significantly with laboratory estimates, which assumed a three-quarters reduction in pollution.

Researchers studied data from in-vehicle energy use monitors of 800,000 cars sold in Europe from 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab estimates, up from three and a half times in 2021.

“Actual emissions are rising, while official emissions are falling,” stated a senior analyst participating in the report. “That discrepancy is widening and poses a significant issue. As a result, PHEVs pollute nearly as much as gasoline vehicles.”

Key Reasons Behind the Emissions Gap

Analysts linked most of the difference to inflated estimates of the “electric driving share” – the percentage of kilometers travelled in battery power relative to total mileage. They found that only 27% of driving was done in EV mode, whereas official estimates suggested over four-fifths.

Additionally, when operating in electric mode, emission amounts were well above lab projections. This happened because EV motors were not strong enough to operate independently, leading to engines using gasoline for nearly a third of the distance completed in EV mode.

Policy and Financial Implications

Based on estimates, the lowballing of PHEV CO2 output enabled four major carmaker companies to avoid more than €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ targets.

Furthermore, owners of PHEVs could spend approximately €500 extra per year in running costs than would be assumed under laboratory conditions.

“The strong statements that manufacturers often promote about their PHEV vehicles are obviously far from the mark,” stated a transport analyst. “Consumers are being misled into believing that by buying a PHEV, they are benefiting the planet and cutting money. Actually, PHEVs are only slightly improved than regular gas and diesel cars in terms of fuel consumption, CO₂ emissions, and operating costs.”

Political Debate and Automotive Lobbying

Hybrid vehicles have lately been brought again into policy discussions as automakers have lobbied the EU to weaken CO₂ targets. A proposed ban on sales of new internal combustion cars in 2035 has faced heavy pressure from the car industry and resistance from EU countries with significant car industries.

Several senior politicians have proposed PHEVs as a potential “compromise” solution to introduce in the legislation.

One independent energy policy expert, who was not involved with the research, called the report a “highly valuable addition” after a long period in which segments of the automotive industry argued there was too little information to properly evaluate real-world emissions.

“The results show, beyond any doubt, that the difference in lab and actual PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or diesel cars,” they said. “All policy changes concerning PHEVs should be made with extreme care and considering that evidence.”