The study found that plug‑in hybrids consume far more fuel than reported.

Brief on the study results

A recent Fraunhofer Institute study found that the claimed fuel consumption figures for plug‑in hybrids (PHEVs) are significantly higher than actual values. On average, these vehicles consume almost three times more gasoline/diesel than regulators prescribe.

What “purebred” electric cars are and why they lost popularity
- Five years ago car enthusiasts actively discussed the advantages of fully electric vehicles.
- Since then the market has shifted toward hybrids with plug‑in capability: they promise greater fuel efficiency, ease of use, and a lower carbon footprint.

How PHEVs work “on paper”
Electrek notes that when regularly charging the battery, the driver can:
1. Drive mainly on electricity (for short trips).
2. Use the internal combustion engine (ICE) only less often and only when necessary.
Actual measurement results
| Indicator | Claimed (WLTP) | Actual | Difference | Average fuel consumption (full cycle) |
|-----------|----------------|--------|------------|--------------------------------------|
| 1.57 L/100 km | 6.12 L/100 km ×3.26 | 2.98 L/100 km | almost twice higher |

The study covered 981,035 European vehicles.

What this means for buyers
- Cheap hybrids are charged from the grid more often than expensive models.
- Premium brands (Porsche, Ferrari, Bentley) actually use fossil fuel almost as frequently as more affordable options.

Implications for regulators
- In Europe real ICE consumption exceeds the WLTP metric by 20 %.
- For PHEVs the gap can reach a four‑fold increase.
- This gives automakers additional incentives but requires revising calculation methods.

Some experts propose a mandatory charging interval: at least once every 500 km of travel.

Conclusion
Plug‑in hybrids consume significantly more fuel in real use than manufacturers and regulators promise. To assess their environmental performance more accurately, WLTP standards need updating and possibly the introduction of requirements for regular battery charging.