Skip advert
Advertisement

Gap between official and real-world fuel economy grows to 42 per cent

Fresh research reveals average gap between quoted and real-world fuel consumption has risen from nine per cent in 2001 to 42 per cent today

real world and official fuel economy gap grows

The average gap between a car’s official fuel economy figures and those obtained in real-world driving conditions has leapt to 42 per cent, new research has found. 

The International Council on Clean Transportation (ICCT) analysed data from over a million vehicles in eight European countries, including the UK, to reach its findings. The latest 42 per cent discrepancy follows 2013 data that found a 25 per cent average gap between advertised and real-world economy in 2013; back in 2001, the discrepancy was just nine per cent. 

Advertisement - Article continues below

Privately-owned cars fared slightly better than company cars, with the former posting an average 39 per cent discrepancy and the latter a 45 per cent difference between official and achieved economy. The ICCT estimates consumers pay £350 extra a year for fuel as a result of these differences. 

These figures may well improve in the future, however, thanks to the introduction of a new WLTP testing procedure for economy and emissions. This new regime was introduced in September 2017 and will become mandatory for all new cars from September 2018. The WLTP procedure replaces the outgoing NEDC assessment programme, which saw cars tested for just 20 minutes in order to ascertain emissions and fuel economy. 

Despite the new testing regime, the ICCT says more may need to be done to address the cap between official and reported economy, as the new WLTP programme: “contains new loopholes that could permit the performance gap to increase again.”

Do you think a 42 per cent difference between quoted and real-world fuel economy figures is acceptable? Let us know below...

Skip advert
Advertisement
Skip advert
Advertisement

Most Popular

MG’s IM brand to launch third model in UK in 2027
MG IM6 - rear detail

MG’s IM brand to launch third model in UK in 2027

Big seven-seat SUV is on the cards for MG’s posh sub-brand
News
2 Oct 2026
New Citroen 2CV: the French £13k EV city car is sticking to retro styling
New Citroen 2CV teaser - headlight

New Citroen 2CV: the French £13k EV city car is sticking to retro styling

New budget-focused EV will closely follow the design of the original 2CV
News
5 Oct 2026
It’s hard to see how the Jaguar Type 01 will be a huge success
Rutherford Jaguar Type 01

It’s hard to see how the Jaguar Type 01 will be a huge success

Mike Rutherford warns that the majority of new car buyers do not go for big, expensive saloon cars such as the latest Jag
Opinion
5 Oct 2026

Find a car with the experts