Plug-in Hybrids Pollute Almost As Much As Petrol Cars, Report Finds
Summary
A new analysis by the non-profit Transport and Environment, reported by The Guardian and summarised on Slashdot, finds that plug-in hybrid electric vehicles (PHEVs) emit far more CO2 in everyday use than official lab tests suggest. Using onboard fuel-consumption meters from about 800,000 European cars (2021–2023), the researchers show real-world emissions for PHEVs are substantially higher than the standardised test results.
Key figures: PHEVs delivered only around a 19% CO2 reduction versus petrol/diesel in real-world driving — far below the 75% reduction assumed under laboratory testing. Real-world emissions in 2023 were 4.9 times greater than test values (up from 3.5x in 2021). The study also found drivers spent much less time in electric mode than tests assume.
Key Points
- The study analysed onboard fuel meters from ~800,000 cars registered in Europe between 2021 and 2023.
- Real-world CO2 savings for PHEVs are around 19% compared with petrol/diesel — not the 75% suggested by lab tests.
- In 2023, PHEV emissions were 4.9 times higher than standardised laboratory test results; that multiplier rose from 3.5 in 2021.
- Drivers are using electric mode far less than assumed in test protocols (the report cites a much lower share of kilometres driven electrically than manufacturers assume).
- Implications include questions over subsidies, tax breaks and whether PHEVs are being used to meet fleet-emission targets without delivering real-world reductions.
Context and Relevance
The findings matter for consumers, regulators and policymakers. If PHEVs routinely underperform in the real world, incentives and regulatory credits that treat them as near-equivalents to full electric vehicles risk undermining climate goals. The report feeds directly into current debates in Europe about post-2035 vehicle rules, manufacturer lobbying, and how to calibrate testing protocols so they reflect everyday behaviour rather than idealised use.
Why should I read this?
Short version: if you care about whether the cars being pushed as “green” actually cut emissions, this is worth a quick skim. It calls out a big gap between lab promises and what people actually do — so if you’re buying a PHEV, making policy, or just fed up with greenwash, this saves you the headache of digging through the full report.