Plug-in hybrids emit six times more CO‚ in everyday use than officially stated

Plug-in hybrid vehicles emit on average six times more CO₂ in real-world driving than stated in official type approval. This is according to an analysis by the environmental organization Transport & Environment, which is based on new EU real-world driving data. The discrepancy between paper and road has thus widened further compared to the previous year. Continue after ad The environmental organization is publishing this data against the backdrop of a possible tightening of the regulations for the Utility Factor (UF) by the EU in November and the preceding discussion of the topic in the EU Council in mid-October. The latter is the assumed proportion of electrically driven kilometers in the WLTP test. One accusation is that too few PHEV drivers actually behave this way and that the UF therefore inadequately reflects reality. The European Automobile Manufacturers' Association and the German federal government have already positioned themselves against a tightening. The evaluation is based on on-board data from the European Environment Agency of around 220,000 plug-in hybrids first registered in 2024. On-Board Fuel Consumption Monitoring devices (OBFCM), mandatory since 2021 in all new passenger cars with internal combustion engines, record actual fuel consumption during driving. This makes the evaluations possible. According to Transport & Environment, the real-world emissions of the 2024 PHEVs are an average of 145 g CO₂/km, while the official WLTP values for the same vehicles only indicate 24 g CO₂/km. Particularly noteworthy: the gap has widened significantly within a year. In 2023, real-world PHEV emissions were still 138 g CO₂/km with an official value of 28 g CO₂/km, corresponding to a factor of around five. According to T&E, the widening gap is because WLTP values decreased by 15 percent due to larger batteries and optimized test conditions, while real-world emissions increased by 5 percent. Conventional combustion engines average 169 g CO₂/km. This means PHEVs are now only 14 percent below that in reality, compared to 17 percent a year ago. Increase in deviation for PHEV real-world consumption. (Image: T&E) Lucien Mathieu, Director of Passenger Cars at T&E, described plug-in hybrids as 'one of the biggest greenwashing stunts of the auto industry: marketed as a green solution, but with significant environmental consequences in practice'. Furthermore, PHEVs are 'a rip-off for consumers who end up paying far more for fuel than expected'. Utility Factor in political crossfire So far, a PHEV with 60 km of electric WLTP range has been assumed to have an electric share of around 80 percent, leading to extremely low paper values. The EU Commission has decided on a phased tightening: since 2025, a reduced UF (Stage 1, about 50 to 54 percent electric share) applies, and Stage 2 is to follow from 2027, which would reduce the assumed electric share to around 30 to 34 percent. This would be significantly closer to the reality of OBFCM data. Continue after ad However, this second stage is under massive political pressure. The European manufacturers' association ACEA is calling for the planned UF tightening from 2027 to be scrapped without replacement. The VDA is pushing for a suspension until the ongoing CO₂ regulatory review is completed. The German federal government is also apparently taking an industry-friendly stance: according to reports, there is a consensus within the federal government to reject the tightening of CO₂ values for hybrid vehicles planned for 2027. This contradicts the climate protection goals for the transport sector set by the Climate Protection Act. More on hybrid drives Opinion: Plug-in hybrids under fire - with old arguments heise autos Consequences for manufacturers and fleet balances For German premium manufacturers like BMW, Mercedes-Benz, Audi, and Volkswagen, with a high proportion of PHEVs in their fleet mix, a halt to the UF tightening would have far-reaching consequences: they could continue to report very low paper emissions through PHEVs and thus mathematically meet the EU fleet targets by 2030, even though real-world emissions are hardly below combustion engine levels. The ICCT estimates, according to media reports, that PHEVs in the EU between 2021 and 2025 have emitted around 100 million tons more CO₂ than officially reported. This corresponds to about two-thirds of the annual emissions of the entire German road transport sector. The situation is also becoming explosive from a consumer law perspective. EU consumer law prohibits misleading information about essential product characteristics such as environmental impact. The new EU directive 'Empowering Consumers for the Green Transition', which fully enters into force in 2026, further tightens the requirements for environmental claims. Consumer associations like BEUC have already filed greenwashing complaints against energy companies. Similarly structured proceedings against car manufacturers for systematically understated PHEV consumption figures would be conceivable. Decision in the autumn Negotiations on the revision of EU fleet limits are ongoing: the Council of the EU will debate on October 12 in the Environment Council, and the EU Parliament will vote in November. T&E warns against weakening the Utility Factor tightening. According to T&E, the industry is asking the EU to 'look the other way so that they can further postpone investments in fully electric vehicles'. PHEVs currently have a market share of 9.8 percent of new EU registrations. (fpi)