Rebound effects of power enhancement in internal combustion and electric vehicles

Regulations and public expectations are compelling the road transport sector to innovate for higher vehicle efficiency. However, a persistent gap remains between official figures and real-world energy performance. This discrepancy is often linked to idealized testing environments and behavioral "rebound effects," where improved efficiency leads to increased travel. This study introduces the "power rebound effect," a new premise where increased horsepower impedes the deployment of efficiency gains. Analyzing a database of 531 car models from 15 years of real-world European testing, our findings reveal a significant power rebound effect in petrol and diesel cars, though not in electric ones. Additionally, rising vehicle weight induces a rebound effect across all vehicle types. This research provides a fuller understanding of the factors shaping passenger car fuel intensity, offering crucial insights for future energy policy.