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PHEVs emit nearly five times more planet-heating pollution than lab-reported figures show, as per a recent analysis.

Widening Discrepancy In Lab and Actual Emissions

Data reveals that PHEVs emit just one-fifth lower CO₂ than conventional petrol and diesel vehicles, based on analysis carried out by a advocacy organization. That differs sharply with laboratory estimates, which suggested a three-quarters decrease in pollution.

Researchers studied information from onboard fuel consumption monitors of 800,000 cars registered in Europe between 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were nearly five times greater than lab estimates, up from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are falling,” stated a senior researcher participating in the study. “This discrepancy is growing and creates a serious issue. Consequently, PHEVs emit almost as much as petrol vehicles.”

Key Factors Behind the Emissions Gap

Analysts attributed most of the gap to inflated estimates of the “electric driving share” – the percentage of kilometers driven in battery mode relative to total mileage. The team determined that just 27% of travel was done in EV mode, whereas official estimates assumed over four-fifths.

Additionally, when operating in electric mode, emission amounts were significantly higher than lab estimates. This happened because electric motors were insufficiently powerful sufficient to function independently, resulting to combustion motors burning gasoline for nearly a third of the travel completed in electric mode.

Regulatory and Financial Implications

Based on calculations, the underestimation of PHEV emissions allowed several large carmaker groups to avoid more than €5bn in fines between 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ standards.

Furthermore, drivers of PHEVs could spend about €500 extra per year in operating costs than is estimated under lab tests.

“The bold claims that manufacturers often promote about their PHEV vehicles are obviously far from the mark,” stated a automotive expert. “Buyers are being duped into believing that by purchasing a PHEV, they are helping the planet and saving costs. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of fuel use, CO₂ production, and running costs.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have lately been brought back into policy debates as automakers have pressed the EU to relax CO₂ standards. A planned prohibition on new combustion engine vehicles in 2035 has faced heavy pressure from the automotive industry and resistance from member states with significant automotive industries.

Several high-level politicians have suggested PHEVs as a possible “compromise” solution to include in the legislation.

One external energy economics specialist, who was unaffiliated with the research, called the analysis a “very useful addition” after a long period in which parts of the car industry claimed there was too little information to accurately evaluate real-world CO2 output.

“The results show, without question, that the gap between official and actual PHEV fuel consumption and CO₂ output is significantly greater than for petrol or diesel vehicles,” they said. “Any regulatory adjustments regarding PHEVs should be implemented with extreme care and considering that evidence.”