Your car guzzles much more fuel and money than you think.


Fuel consumption results obtained in the laboratory and on the road, in real-world driving conditions, were compared by the International Council on Clean Transportation (ICCT).

Here is what they found:

Private drivers consume 39% more fuel than on paper
Company cars drivers consume 45% more fuel than on paper
On average, drivers consume 42% more fuel than on paper

And this gap is growing bigger and bigger:


How is it possible?

Before the emission tests in the laboratory, carmakers optimise their cars in a way that is not representative of real-driving conditions. By doing so, they manage to reduce, on paper, fuel consumption and CO2 emissions.

For example, they:

  • use so-called “fuel saving” technologies, like stop-start systems ⓘ, that makes cars more efficient during the test in the lab, but not on the road.
  • make the most of test loopholes, including defeat devices ⓘ, to reduce emissions on paper.
  • switch off part of the car equipment, such as air conditioning and lights, during the test.

Here is an overview of the ways the official data can be manipulated:


Infography showing loopholes used by carmakers to reduce CO2 emissions

This picture shows how manufacturers have manipulated official fuel consumption data of passenger cars under the NEDC (New European Driving Cycle) certification procedure. As of September 1, 2017, new car models have to pass a newly developed lab test procedure, the WLTP (Worldwide Harmonized Light Vehicle Test Procedure), before they can be driven on EU roads. While the WLTP reduces some of the loopholes available in the NEDC, it has the potential for manipulation and exploitation of flexibilities, as does any lab test procedure. Unless effective surveillance mechanisms are introduced, carmakers will be able to exploit the loopholes in the WLTP and the discrepancy between official and real-world fuel consumption values will continue to increase.

What does it imply?

This fraud has huge consequences for the consumer, the economy and the environment.


Economy and Consumers

In the EU, people spend more money on transport than on food.

Find out more


In Europe, 12% of CO2 emissions come from cars.

Find out more


To stay competitive, the European car industry must invest in innovations, not in trickery.

Find out more



80% of EU oil imports is now supplied by non-European companies.

Find out more

We must close the gap

Consumers must be able to buy cleaner and cheaper vehicles, with fuel consumption figures they can trust.

Carmakers have been able to achieve, on paper, good fuel economy results. But this is only due to optimisations, flawed tests, the absence of spot checks on cars already sold, and the difficulties for consumers in taking action against unrealistic fuel consumption figures.

To tackle global warming, save consumers money, keep European carmakers competitive and reduce the EU's dependency on imported oil, we must close the gap between official and real fuel consumption figures. 


How can we close the gap?


Interview with Antonio Toccarelli, project manager at Altroconsumo

“It should be made clear to consumers that fuel consumption declared values derive from laboratory tests and that there is always a gap of at least 20% with consumption values registered in real driving conditions.”

Consumer tips for dealing with the additional fuel consumption of passenger cars

A modern car now consumes on average 39% more fuel than specified by the manufacturer

Honest fuel consumption figures of passenger cars

The actual fuel consumption of new passenger car models increasingly differs from the official specifications of the manufacturers.

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