Real-world fuel economy figures revealed

The gap between advertised and on-the-road MPG is now at its widest ever point, with just one in 10 cars managing to hit their official fuel economy figures, according to new claims.

Motoring website analysed 118,000 Real MPG fuel reports, submitted by UK drivers, and found that an average car now uses 24% more fuel than it should.

The BMW X5 is the UK’s worst performing car for Real MPG, achieving 66.9% of its advertised fuel economy, followed by the Land Rover Discovery Sport and Audi A4 with a respective 67.5% and 68.3%.

At the opposite end of the scale the latest Mazda MX-5 is the UK’s best Real MPG performer, with an average of 101.5%.

Real MPG was launched in 2011 after received thousands of complaints from readers that their cars could not match the ‘official’ EC fuel economy figures.

Real MPG invites motorists to submit how many miles their cars actually do to the gallon, covering all major makes and models.

Unlike official (laboratory tested) fuel consumption figures, Real MPG gives real life comparative data and allows car owners and buyers to see how much on-the-road fuel a vehicle really uses.

One of the reasons new cars have performed increasingly poorly is because, since 2015, car manufacturers have been fined if the corporate average CO2 emissions of their cars exceeds 130g/km according to MPG and CO2 laboratory tests. To avoid the fines, vehicles are increasingly optimised for the laboratory test at the expense of reality.

From September 2017, the current NEDC (New European Driving Cycle) test for new cars will be replaced with the Worldwide Harmonised Light Vehicles Test Procedure (WLTP). However, while the WLTP should be more reflective of real world driving conditions and involve longer distances and higher speeds, it will still be laboratory-based.

“Real MPG has shown that, for the majority of drivers, advertised fuel economy figures are quite simply too good to be true,” explained Honest John’s Managing Editor, Daniel Powell.

“As a result, many are finding it increasingly difficult to understand how much fuel a car will use or how polluting it will be.

“We welcome the introduction of the new Worldwide Harmonised Light Vehicles Test Procedure (WLTP), but it remains to be seen if this new laboratory-based test will provide the realistic figures that the public have been crying out for – there’s clearly a need for change in the way that MPG is measured, as the real world figures don’t reflect those of laboratories.”

Top 10 worst cars in terms of disparity between claimed and Real MPG fuel economy:

 1) BMW X5  66.9%
 2) Land Rover Discovery Sport  67.5%
 3) Audi A4  68.3%
 4) Volvo XC90  68.5%
 5) Fiat 500X  69.6%
 6) MINI Hatch  70.0%
 7) Peugeot 308SW  70.2%
 8) Range Rover Evoque  70.4%
 9) Ford Fiesta  71.0%
 10) Hyundai Tucson  71.3%

Top 10 best cars in terms of disparity between claimed and Real MPG fuel economy:

 1) Mazda MX-5 101.5%
 2) Toyota Verso  99.5%
 3) Toyota GT86  98.4%
 4) Subaru Forester  97.1%
 5) Peugeot Partner Tepee  92.9%
 6) Suzuki SX4 S-Cross  92.0%
 7) SEAT Mii  90.6%
 8) Volkswagen Jetta  90.4%
 9) Suzuki Swift  90.1%
 10) Volkswagen Scirocco  88.6%