Plug-in Hybrid electric Cars Pollute Nearly as Heavily as Gasoline Cars, Report Reveals

Plug-in hybrid cars emit almost 5x greater global warming emissions than official data indicate, according to a recent report.

Widening Discrepancy Between Lab and Real-World Emissions

Statistics reveals that PHEVs release only one-fifth less CO₂ than traditional petrol and diesel vehicles, according to research carried out by a advocacy organization. That differs significantly with laboratory estimates, which suggested a three-quarters reduction in emissions.

Analysts examined information from onboard energy use meters of 800,000 cars sold in the EU between 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were nearly five times higher than lab figures, up from 3.5 times in 2021.

“Actual emissions are increasing, while official emissions are decreasing,” said a lead analyst participating in the report. “That discrepancy is widening and poses a serious problem. As a result, PHEVs emit almost as much as gasoline cars.”

Primary Reasons Driving the Emissions Gap

Analysts linked the majority of the difference to overestimates of the “electric driving share” – the percentage of miles driven in battery mode relative to total distance. The team determined that only a quarter of travel was done in EV mode, whereas lab estimates assumed over four-fifths.

Even, when operating in electric mode, emission amounts were well above official estimates. That happened because EV motors were insufficiently powerful enough to operate independently, resulting to engines using fossil fuels for almost one-third of the travel completed in EV mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV CO2 output enabled several major carmaker groups to avoid over €5bn in fines between 2021 and 2023, by falsely simplifying adherence with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs could pay about €500 more per year in operating costs than is assumed under laboratory tests.

“The strong statements that automakers like to make about their PHEV cars are clearly way off the truth,” commented a automotive analyst. “Buyers are being misled into thinking that by buying a PHEV, they are helping the environment and saving costs. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of energy consumption, CO₂ emissions, and running costs.”

Policy Debate and Industry Pressure

Plug-in hybrid cars have lately been brought again into policy discussions as carmakers have pressed the European Union to relax CO₂ targets. A planned prohibition on sales of new internal combustion cars in 2035 has faced heavy lobbying from the automotive sector and resistance from EU countries with large car industries.

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

One external energy economics specialist, who was not involved with the research, described the report a “very useful contribution” after years in which parts of the car industry claimed there was insufficient information to accurately evaluate actual CO2 output.

“These findings show, without question, that the gap in lab and real-world PHEV fuel consumption and CO₂ output is much, much larger than for gasoline or conventional vehicles,” the expert said. “All regulatory adjustments concerning PHEVs should be implemented with extreme caution and considering this data.”