For years, plug-in hybrids were promoted as a climate-friendly bridging technology between electric vehicles and conventional combustion engines. Particularly low WLTP fuel consumption figures, tax advantages, and government subsidy programs made these vehicles economically attractive to many buyers. Manufacturer specifications often suggested fuel consumption of just one to two liters per 100 kilometers – provided the vehicle was used predominantly in electric mode.
Current studies However, other sources paint a different picture. Numerous vehicle owners report significantly higher real-world fuel consumption. This raises the central legal question: Does a substantial discrepancy between official fuel consumption figures and actual everyday consumption constitute a material defect within the meaning of Section 434 of the German Civil Code (BGB)?
New Fraunhofer study: Real-world consumption up to 300 percent higher
A recent study by the Fraunhofer Institute for Systems and Innovation Research (ISI), based on real driving data from around one million plug-in hybrid vehicles from the years 2021 to 2023, comes to a clear conclusion: The average real fuel consumption is around six liters per 100 kilometers – and thus around three times higher than many official WLTP figures.
What's remarkable is the data basis. Unlike traditional test bench investigations, this study analyzed real-world driving data from the road, transmitted digitally by the vehicles. This makes it the first study to systematically depict actual everyday use.
Why is the combustion engine activated more frequently?
Many buyers assumed they would be able to operate their vehicle almost exclusively on electric power. In practice, however, it turns out that the combustion engine starts up significantly more often than expected.
The causes include climatic conditions, performance demands during acceleration, software-based protection mechanisms for the battery, and real-world driving profiles that deviate significantly from the standardized WLTP test cycle. Even in predominantly electric mode, measurable fuel consumption occurs.
This raises the question for many affected individuals as to whether the advertised consumption figures are realistically achievable under everyday conditions.
Legal classification: When does a material defect exist?
According to § 434 of the German Civil Code (BGB), an item is defective if it does not possess the agreed-upon or customary quality. In particular, it is decisive whether the consumption specifications have become part of the contractually owed quality or at least give rise to a legitimate expectation of the buyer.
The courts have repeatedly ruled that significant and lasting discrepancies between prospectus information and actual consumption values can constitute a defect – especially if the information was decisive for the purchase.
Depending on the individual case, the following claims may be considered:
- withdrawal from the purchase contract
- Purchase price reduction
- damages
- Challenge due to fraudulent misrepresentation
- Potential tort claims against the manufacturer
Especially in light of the case law related to the diesel scandal, courts are increasingly critically examining whether manufacturers' information was suitable to economically influence consumers.
Parallels to the diesel scandal?
Also in diesel scandal Officially approved test bench results were in significant contradiction to real-world driving conditions. While the technical reasons differ, the legal question remains whether inherently unrealistic testing procedures present a distorted picture of actual usage.
Should structural and systematic deviations be confirmed, this could create a new area of liability for manufacturers.
Tax advantages and subsidies – a poor economic decision?
Many buyers opted for a plug-in hybrid due to financial incentives such as the 0.5 percent rule for company cars, environmental bonuses, or favorable CO₂ ratings.
However, if actual consumption proves to be significantly higher, this can considerably alter the economic calculations. In such cases, the question arises whether the purchase decision was based on inaccurate consumption assumptions.
Have your claims legally reviewed now.
Current research suggests that numerous buyers of plug-in hybrid vehicles may have been economically disadvantaged.
Whether your specific case involves a material defect, a misleading consumption statement, or a claim for rescission or compensation depends on the individual circumstances.
We will review your contract documents, the advertised consumption figures, and your actual usage situation, and assess possible warranty or tort claims.
Get your case legally assessed now, free of charge and without obligation.
The sooner you act, the better you can protect your rights.
