Miles off the mark? WhatCar? slams fuel use figures

Think you can trust government-approved figures on how many miles a certain make and model of car will do on a gallon of fuel? Well, think again. Research from WhatCar? suggests official fuel economy figures are well wide of the mark, with the typical mile per gallon (MPG) rate 19% lower than the level suggested by manufacturers and dealerships.
As an aside – why’s it still miles per gallon?

Grand deception?

WhatCar? reckons new car buyers who use the government-sanctioned numbers to work out how much they are likely to spend on petrol or diesel in the first three years of ownership will find themselves some £1,000 out of pocket on average. So why are official MPG figures so inaccurate? The main problem with official MPG figures is that they are worked out under laboratory conditions that can rarely be replicated in the real world. Jim Holder at WhatCar? said: “It’s clear the official test processes need to be updated so that car buyers can place more trust in the figures they are being told.”

Back in the real world…

WhatCar? has been using experienced engineers to drive test vehicles on a variety of real roads, including motorways and A and B roads for two years. And in that time, it has tested almost 400 cars in real-world conditions. This has given it the ammunition to challenge the laboratory-based figures, against which its results show a typical reduction approaching 20% in some cases.

Consumption confusion

While the official MPG consumption of the Kia Rio 1.1 CRDi EcoDynamics, for example, is 88.3, the WhatCar? tests show the true level to be 70.6 – a difference of 17.7 miles for every gallon of fuel bought. The government-approved figures relating to the Vauxhall Corsa 1.3 CDTi Ecoflex S, meanwhile, are even more misleading. They claim that it does 85.6 miles to the gallon, whereas the WhatCar? engineers found the little car could only squeeze an average of 61.4 miles out of each gallon in realistic driving conditions. Holder said: “Our true MPG tests are the only reliable source of real-world fuel economy.” You can check the true fuel economy level of your car, or a car you are thinking of buying, using the What Car? True MPG online tool.

Dirty deals?

As part of its research into MPG figures, What Car? also went mystery shopping in 100 dealerships, asking for information on the fuel economy of various models from eight big manufacturers: Audi, Toyota, Volkswagen, Nissan, Peugeot, Renault, Ford and Dacia. And it’s main finding was that dealership salespeople often either stuck rigidly to official data or avoided answering questions on fuel efficiency altogether. Holder said: “Car dealers and the car industry aren’t obliged to advise consumers about fuel economy beyond pointing at official statistics. “We’d like to see more transparency at play, with dealers pointing to True MPG to give customers a realistic expectation of what fuel economy they can expect.” Have you noticed a big discrepancy between your car’s advertised fuel consumption figures and what you actually achieve? Let us know in the box below…

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