A growing body of evidence shows the current test used to measure car fuel efficiency is outdated, unrepresentative of real-world driving and lax enough to allow carmakers to systematically manipulate official test results at the expense of consumers’ trust.
European institutions are presently finalising a regulation to lower CO2 emissions from cars and vans in 2020. This has stimulated intense debate when and how a new official test should be introduced. This briefing informs this debate in the light of new evidence from the International Council on Clean Transportation (ICCT) that for the first time compares progress in official and real-world vehicle fuel efficiency on a brand-by-brand basis.