Plug in Hybrid Cars Pollute Nearly as Much as Petrol Cars, Study Reveals

PHEVs release almost five times greater planet-heating pollution than lab-reported data indicate, as per a new report.

Widening Gap Between Lab and Actual CO2 Output

Data reveals that PHEVs release only one-fifth lower CO₂ than traditional petrol and diesel cars, according to research conducted by a non-profit organization. That contrasts sharply with lab estimates, which suggested a 75% reduction in pollution.

Analysts studied data from in-vehicle fuel consumption monitors of eight hundred thousand cars registered in the EU between 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were nearly five times higher than official estimates, increased from three and a half times in 2021.

“Actual emissions are increasing, while lab-reported emissions are decreasing,” stated a lead researcher participating in the report. “This discrepancy is widening and creates a significant problem. Consequently, PHEVs pollute nearly as heavily as petrol vehicles.”

Key Factors Behind the Discrepancy

Analysts linked most of the gap to inflated estimates of the “utility factor” – the percentage of kilometers driven in electric mode compared to overall mileage. The team determined that just a quarter of travel was done in electric mode, whereas official estimates suggested over four-fifths.

Additionally, when operating in EV mode, emission amounts were well above lab estimates. This occurred because EV motors were insufficiently powerful enough to function independently, resulting to engines using fossil fuels for almost one-third of the distance covered in EV mode.

Regulatory and Economic Consequences

According to calculations, the lowballing of PHEV CO2 output enabled four large automaker groups to escape over €5bn in fines between 2021 and 2023, by artificially easing adherence with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs could pay approximately €500 extra per year in running costs than would be estimated under laboratory tests.

“The strong statements that automakers like to make about their PHEV cars are obviously far from the mark,” stated a transport expert. “Buyers are being duped into thinking that by buying a PHEV, they are benefiting the environment and cutting costs. Actually, PHEVs are little better than standard petrol and diesel vehicles in terms of energy use, CO₂ production, and running costs.”

Policy Discussion and Industry Lobbying

Hybrid vehicles have recently been drawn again into policy debates as automakers have lobbied the European Union to weaken CO₂ standards. A planned ban on sales of new internal combustion cars in 2035 has faced heavy lobbying from the automotive sector and resistance from member states with significant automotive industries.

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

One external energy policy specialist, who was unaffiliated with the study, called the report a “very useful addition” after years in which parts of the automotive sector claimed there was insufficient information to accurately assess real-world CO2 output.

“These findings demonstrate, without question, that the difference between official and actual PHEV energy use and CO₂ emissions is significantly greater than for petrol or diesel vehicles,” they said. “Any policy changes regarding PHEVs should be implemented with utmost caution and considering this evidence.”