Do technical improvements lead to real efficiency gains? Disaggregating changes in transport energy intensity
This paper uses driver reported data and shows that the real fuel efficiency of new cars in Great Britain has improved by far less than widely reported. This is because vehicle testing procedures used in the European Union are not representative of real world driving. Using regression techniques, we were able to quantify the real technical efficiency improvements (from e.g. improved combustion, aerodynamics and lightweight materials) of new vehicles between 2001 and 2018. We show that 60% of technical improvements were offset by increasing vehicle size and power. In 2008/09, the EU introduced mandatory CO2 emissions standards for all new vehicles sold in Europe. This paper shows that these policies had little impact on the rate of technical efficiency improvements. This study adds to the growing literature calling for official test procedures to be representative of real-world driving.
Read the full paper published in the journal of Energy Policy here: