Q. A Peugeot I test-drove recently claimed 90mpg; I managed 47mpg. Why the discrepancy?
CC, Chippenham, Wiltshire
A. Car makers have become adept at designing to the laboratory test, which was last updated in 1997. They design cars with gear ratios and engine settings that will ensure a good result. The International Council on Clean Transportation says real-world and test figures now deviate by about 40%.
Hybrid cars can have even greater discrepancies than standard petrol or diesel-powered vehicles.
However, a new test is due to be introduced in 2017 that will more accurately reflect real-world MPG, with manufacturers forced to publish results.
TIM’LL FIX IT
Tim Shallcross used to train AA patrols to fix cars. Now he advises the Institute of Advanced Motoring — read more from Tim here.
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