Plug-in Hybrids Use Triple the Fuel Claimed by Manufacturers, Study Reveals
A comprehensive new analysis has uncovered that plug-in hybrid vehicles are using approximately three times more fuel than manufacturers officially claim. While most hybrids are advertised as consuming between one and two litres of fuel per 100 kilometres, the study indicates they actually require an average of six litres per 100km in real-world conditions.
Real-World Data Analysis
The Fraunhofer Institute conducted this revealing research by examining data transmitted wirelessly from plug-in hybrid vehicles while they were actively being driven on roads. The vehicles included in the study were all produced between 2021 and 2023, representing a modern sample of hybrid technology.
This transmitted data allowed analysts to determine precise, real-world fuel consumption figures that differ dramatically from laboratory test results. According to the study findings, these vehicles need about 300% more fuel to operate than previously cited by manufacturers.
Manufacturer Responses and Legal Compliance
Patrick Plötz of the Fraunhofer Institute shared his perspective with German broadcaster SWR, suggesting potential consequences for manufacturers. "Then one could say a manufacturer who does not comply with the emissions limits on the road may have to pay a penalty," he stated.
Porsche responded to the study by referencing "differing usage patterns" that influence fuel consumption. The automaker insisted its fuel consumption measurements strictly adhere to legal requirements. "The fuel consumption figures of our vehicles are based on the legally prescribed EU measurement procedures," the company told SWR.
Porsche further explained that these procedures ensure "uniform and comparable values across Europe," while acknowledging that "deviations from individual real-world consumption figures can arise due to different usage profiles and external conditions," including road conditions and driver behavior.
Policy Context and Future Regulations
The study emerges amid significant policy discussions about vehicle emissions and future automotive regulations. The Labour Party government plans to continue allowing hybrid sales after 2030 until 2035, even as new petrol and diesel car sales will be prohibited by the end of this decade.
Meanwhile, the European Union modified its phase-out rules in December, now requiring manufacturers to achieve a 90% reduction in tailpipe emissions from 2035 onward. This regulatory shift creates additional pressure for accurate emissions reporting and real-world performance data.
The discrepancy between claimed and actual fuel consumption raises important questions about testing methodologies, consumer expectations, and environmental impact assessments for hybrid vehicles moving forward.
