The gap between advertised and on-the-road fuel economy is now at its widest ever point say HonestJohn.co.uk, and they have the data to prove it.
HonestJohn.co.uk, a consumer-led motoring website, invited British motorists to share how many miles to the gallon their cars actually covered in real world driving conditions. The fuel economy data could be submitted to their website via a ‘Real MPG’ form.
Over 118,000 reports were lodged, then analysed, and the results found that an average car now uses 24 per cent more fuel than it should.
The UK study found the worst offender was the BMW X5, achieving 66.9 per cent of its advertised fuel economy amongst the surveyed population. The Land Rover Discovery Sport was second on 67.5 per cent and Audi A4 – the only sedan in the top 10 – in third achieving 68.3 per cent.
“Real MPG has shown that, for the majority of drivers, advertised fuel economy figures are quite simply too good to be true,” said Honest John 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.”
“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.”
HonestJohn.co.uk state one of the reasons some new cars have performed 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.
At the opposite end of the spectrum, the HonestJohn.co.uk study found the latest Mazda MX-5 to be the UK’s best Real MPG performer, achieving an average of 101.5 per cent of advertised fuel economy amongst participants.
Second and third of the top performers were the Toyota Verso (not available in New Zealand) and GT86, capable of reaching 99.5 per cent and 98.4 per cent of the advertised economy.
Real MPG was launched in 2011 after Honest.John.co.uk received thousands of complaints from readers that their cars could not match the ‘official’ fuel economy figures.
The worst cars on sale in terms of disparity between claimed and Real MPG fuel economy are:
| 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% |
The best cars on sale in terms of disparity between claimed and Real MPG fuel economy are:
| 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% |