Plug in Hybrid electric Cars Emit Almost as Heavily as Petrol Vehicles, Report Reveals

PHEVs produce almost 5x more planet-heating pollution than official figures show, as per a new report.

Widening Discrepancy In Lab and Actual Emissions

Data shows that PHEVs emit just one-fifth lower CO₂ than conventional petrol and diesel vehicles, according to analysis carried out by a non-profit organization. This differs significantly with laboratory estimates, which suggested a 75% decrease in emissions.

Researchers examined information from onboard fuel consumption monitors of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than official figures, up from three and a half times in 2021.

“Real-world CO2 output are rising, while official emissions are decreasing,” said a lead analyst involved in the report. “That gap is growing and poses a serious problem. As a result, PHEVs pollute almost as heavily as petrol cars.”

Key Factors Driving the Discrepancy

Researchers linked the majority of the difference to overestimates of the “electric driving share” – the percentage of kilometers travelled in electric power compared to total mileage. The team found that just 27% of travel was done in electric mode, while official assumptions suggested over four-fifths.

Even, when running in electric mode, emission levels were well above lab estimates. That occurred because electric motors were insufficiently powerful sufficient to operate independently, leading to engines using fossil fuels for almost one-third of the distance completed in electric mode.

Regulatory and Financial Consequences

According to estimates, the underestimation of PHEV emissions allowed four large carmaker companies to avoid over €5bn in penalties between 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ standards.

Additionally, owners of PHEVs would spend approximately €500 more annually in running costs than would be estimated under lab conditions.

“The strong claims that manufacturers often promote about their plug-in hybrid vehicles are clearly way off the mark,” commented a transport analyst. “Buyers are being misled into thinking that by buying a PHEV, they are helping the planet and saving costs. In reality, PHEVs are little improved than regular petrol and diesel cars in terms of fuel consumption, CO₂ production, and operating costs.”

Political Discussion and Industry Lobbying

Hybrid cars have recently been brought back into political debates as carmakers have lobbied the EU to relax CO₂ standards. A proposed ban on new internal combustion vehicles in 2035 has faced heavy pressure from the automotive sector and resistance from EU countries with significant car industries.

Some high-level politicians have proposed PHEVs as a possible “flexibility” solution to introduce in the legislation.

An independent energy economics expert, who was unaffiliated with the study, called the analysis a “highly valuable contribution” after a long period in which segments of the automotive sector claimed there was insufficient data to accurately evaluate real-world CO2 output.

“The results show, without question, that the gap between official and actual PHEV energy use and CO₂ emissions is much, much greater than for gasoline or conventional cars,” they stated. “All policy adjustments concerning PHEVs should be made with extreme caution and in the light of this data.”