RAC Cars News


Manufacturer MPG Figures Criticised Again

By raccars Published

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Consumer group Which? has criticised auto makers for overstating the MPG figures of their vehicles, after a 200 car test found only one car matched its official fuel consumption. The group is pushing for the testing process to be updated, to reflect real life vehicle usage conditions.

The Which? Report claims that drivers who rely on officially published MPG figures are having to spend far more than they expected on fuel, as fewer than 2% of cars live up to manufacturer published fuel consumption statistics. The consumer group has accused car manufacturers of misleading motorists, after independent testing proved that only three of 200 cars tested could match its official MPG figures.

On average, the cars tested used 13% more fuel per gallon than manufacturers claimed, which adds up to about an extra £133 per year at the fuel pumps for the average car owner.

The Mitsubishi Outlander PHEV came in for particular criticism, as one of the worst performing models, despite a 'clean and green' reputation. The plug in hybrid SUV used 120% more fuel during testing than the amount published by its manufacturer, which adds up to about £459 more per year in fuel costs than owners would expect.

However, the Jeep Grand Cherokee offered the biggest surprise expense of all, with fuel usage understated by 55%, for an extra fuel cost of £854 per year. The BMW 4 Series Gran Coupe, the BMW X4 and the Volvo V60 Plug-In Hybrid all also performed far worse than manufacturers' claims in real world testing.

The consumer group has blamed the official testing process for the discrepancies, claiming that it is full of loopholes which manufacturers can exploit, to artificially inflate the level of efficiency of their vehicles. Tricks used by manufacturers to obtain the best fuel economy results during testing include overinflating tyres to lower rolling resistance, running the car in 'eco' mode only, turning off air conditioning and lights, removing fittings to reduce weight and taping up gaps in bodywork, to reduce air resistance.

This means the testing process does not at all reflect real world driving scenarios. The EU plans to introduce a more realistic testing process in 2017 but manufacturers are objecting to the new system and trying to delay its introduction until 2020. Which? believes that this could cost unsuspecting motorists unfairly and has encouraged the European Commission to stand firm.

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