🔗 Share this article

PHEVs produce nearly five times more planet-heating emissions than official figures show, according to a new report.

Growing Discrepancy Between Lab and Actual Emissions

Data shows that PHEVs release only 19% less CO₂ than conventional petrol and diesel vehicles, based on analysis conducted by a non-profit organization. That differs significantly with lab tests, which suggested a three-quarters reduction in pollution.

Analysts studied information from in-vehicle energy use meters of 800,000 cars sold in Europe between 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were nearly five times higher than official figures, up from three and a half times in 2021.

“Actual CO2 output are increasing, while official figures are falling,” said a senior analyst participating in the report. “This discrepancy is widening and creates a significant problem. Consequently, PHEVs emit almost as heavily as gasoline cars.”

Key Reasons Behind the Emissions Gap

Analysts attributed the majority of the gap to overestimates of the “utility factor” – the ratio of miles driven in electric mode compared to overall mileage. The team found that only a quarter of driving was done in EV mode, while official assumptions assumed 84%.

Even, when operating in EV mode, pollution levels were well above lab projections. That occurred because electric motors were insufficiently powerful sufficient to function alone, resulting to combustion motors burning fossil fuels for almost one-third of the distance completed in EV mode.

Policy and Financial Implications

According to estimates, the lowballing of PHEV emissions allowed several major carmaker companies to avoid over €5bn in penalties from 2021 and 2023, by artificially easing adherence with EU fleet-average CO₂ standards.

Additionally, owners of PHEVs would pay about €500 extra annually in operating expenses than would be assumed under laboratory tests.

“The bold statements that manufacturers like to make about their plug-in hybrid cars are obviously way off the truth,” commented a transport expert. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are only slightly improved than standard gas and diesel cars in terms of energy consumption, CO₂ production, and running costs.”

Policy Discussion and Automotive Lobbying

Plug-in hybrid vehicles have lately been drawn back into political debates as automakers have lobbied the EU to relax CO₂ standards. A proposed ban on sales of new internal combustion cars in 2035 has faced heavy lobbying from the automotive sector and opposition from member states with large car industries.

Some high-level politicians have proposed plug-in hybrids as a potential “flexibility” option to introduce in the legislation.

An independent energy economics expert, who was not involved with the study, called the report a “highly valuable addition” after years in which segments of the car sector argued there was too little information to properly assess real-world CO2 output.

“These findings show, beyond any doubt, that the difference between lab and real-world PHEV fuel consumption and CO₂ output is much, much greater than for petrol or conventional vehicles,” the expert stated. “Any policy adjustments concerning PHEVs should be made with utmost care and considering that data.”