Economy drive – the family cars that beat their official MPG and those that fall short

Economy drive – the family cars that beat their official MPG and those that fall short
Economy drive – the family cars that beat their official MPG and those that fall short

Tough new fuel economy tests have helped crack down on unrealistic MPG figures but there is still a significant gap between official figures and drivers’ real-world experiences.

New data from a leading motoring consumer group has found that the latest Worldwide Harmonised Test Vehicle Procedure (WLTP) has brought laboratory and real-world results closer together, with some new models managing to exceed their claimed economy.

However, a gap remains between the average results, and some models are still more than 20 per cent less efficient than the official figures state.

Exceeding expectations

The Mazda MX-5, Nissan Qashqai and Skoda Karoq were among five cars found to achieve better-than-claimed miles per gallon in real-world tests by What Car? magazine.

The sporty 2.0-litre MX-5 was an impressive 10.3 per cent more efficient that claimed (45.1mpg v 40.9mpg), while the 1.5-litre petrol version of the Karoq returned 44.2mpg compared to its official rating of 40.9mpg, making it 8.1 per cent less thirsty.

The 2.0-litre Mazda MX-5 outperformed its official figures by 10 per cent
The 2.0-litre Mazda MX-5 outperformed its official figures by 10 per cent

The Qashqai – the sixth best-selling car in the UK – was 3.8 per cent better than official claims in 1.3 petrol guise, just behind the petrol Seat Ateca and diesel Skoda Superb estate.

On average, new models tested by What Car? fell 4.9 per cent short of their official WLTP economy figures – a significant improvement over the 23.5 per cent disparity under the old NEDC regime.

But some cars, including models from Volvo, Ford and BMW continued to disappoint. Volvo’s D4 V60 was more than 23 per cent less economical than the official results suggest, with the 140PS version of the UK’s best-selling car – the Ford Fiesta – more than a fifth (21 per cent) less economical than claimed.

Testing regimes

Across a sample of 15 vehicles, What Car? compared the real-world economy figures achieved under its True MPG test against official recorded figures recorded using the new, tougher-than-ever WLTP tests.

The WLTP was introduced by the European Union in September 2017 to assess new vehicle emissions and fuel economy more accurately. It features a longer assessment, higher driving speeds and a “dynamic” test cycle to more accurately reflect real-life driving. It replaced the NEDC type approval process that dated back to the 1970s and which was criticised for resulting in unrealistic economy claims.

Read more: Diesel Land Rover 20 times less polluting than a Renault Clio

The WLTP tests are designed to be more like real life than the previous NEDC regime. (Picture: Shutterstock)
The WLTP tests are designed to be more like real life than the previous NEDC regime. (Picture: Shutterstock)

Striving for accuracy

Steve Huntingford, editor of What Car?, said: “For years fuel economy figures recorded under the official test regime have been almost unachievable under real-world driving conditions, so it’s great to see that the new, tougher tests have closed the gap so significantly.

“However, while it’s heartening to see some cars actually beating their official figures, we mustn’t lose sight of the fact the gap between official figures and our real-world tests remains, on average, at almost five per cent

“We will keep testing until that gap is gone; until then, for the most accurate fuel economy comparisons, we recommend new car buyers use our What Car? True MPG fuel tool to see what their next vehicle is likely to achieve under genuine real-world driving conditions.”

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