Motorists can determine the "real" fuel economy of their cars, as opposed to the "wildly optimistic" official figures, with the help of a user-generated database.
Launched by Honest John, the Daily Telegraph's motoring expert, the Real Life Fuel Economy Register enables drivers to enter their own daily fuel consumption figures, which the website uses to generate an average mpg.
It can then be compared with the official EC figures, which Honest John believes are often skewed because they rely on simulated conditions in a laboratory.
Cars registered in the database are classified based on make, model, engine and transmission type.
Honest John said there are measures in place to prevent distortion of averages through multiple entries, far-fetched figures or "other forms of sabotage".
"Different types of driving and usage and the experience of thousands of drivers all average out to give an overall figure that you can reasonably expect to achieve," said Honest John.
Official EC "combined" CO2 emission and fuel consumption figures are determined through a series of tests.
According to the expert, they tend to be over-optimistic and not reflect the real-life scenario because manufacturers optimise their engines for the test to achieve the lowest possible CO2 emission which forms the basis of taxation.
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