Fraunhofer Study Finds Some PHEVs Use 3 Times More Fuel Than Claimed
Summary
A Fraunhofer ISI study reveals that several German-built PHEV models consume up to three times more gasoline than manufacturers report, raising concerns about fuel efficiency claims. This finding highlights the need for transparency in hybrid vehicle performance.
Key Insights
Why do PHEVs consume more fuel in real-world driving than manufacturers claim?
PHEVs consume more fuel because the combustion engine activates more frequently than expected, even in electric mode, due to low charging frequency, shorter real-world electric range, and long-distance driving that exceeds battery capacity. Real-world data shows average consumption of 5.9-6 liters per 100 km, compared to WLTP claims of about 1.57 liters per 100 km.[1][2][3]
What is the difference between WLTP fuel consumption claims and real-world usage for PHEVs?
WLTP is a lab-based test (Worldwide Harmonised Light Vehicles Test Procedure) that measures fuel use under idealized conditions, often assuming frequent charging and short trips, resulting in low claims like 1.6-1.7 L/100 km. Real-world usage from nearly 1 million PHEVs shows 3-4 times higher consumption (4.0-8.4 L/100 km), as drivers rarely charge daily and rely more on gasoline.[2][3][7]