Almost every hybrid car on sale in the UK falls short of its official fuel economy claims, according to new measurements.
In the worst cases, hybrid cars – which use a combination of a combustion engine and electric power – are up to 80 miles per gallon (mpg) shy of what manufacturers tell customers they can do.
One of the models that misses its claimed economy is the Mitsubishi Outlander PHEV – the most-bought hybrid car in the UK last year.
Hybrid heist: A new study has revealed that the typical hybrid car in the UK returns just 70% of its advertised fuel economy on average
The startling figures were released by automotive consumer site HonestJohn.co.uk, which has so far conducted 148,000 real-world fuel tests of vehicles to work out how close they are to their claims.
While most models – including petrol and diesel – fall short of their published stats, self-charging hybrids and plug-in hybrids are the most misleading when it comes to fuel consumption.
The motoring site said just one in 39 hybrid models deliver their advertised mpg.
The Mercedes-Benz C-Class C350e is the UK’s worst performer, achieving just 36.9 per cent of its official fuel economy, while the BMW 3 Series 330e and Volkswagen Golf GTE are the second and third worst with a respective 37.2 per cent and 38.1 per cent.
The Mitsubishi Outlander PHEV – the nation’s most-bought plug-in hybrid – was also among the worst offenders, achieving just 42.5 per cent of its claimed 166mpg.
On average, the typical hybrid car in the UK returns just 70 per cent of its advertised fuel economy on average, HonestJohn.co.uk found.
Hybrids furthest away from their claimed fuel economy figures
1. Mercedes-Benz C-Class C350e – achieves 36.9% of claimed mpg
2. BMW 3 Series 330e – achieves 37.2% of claimed mpg
3. Volkswagen Golf GTE – achieves 38.1% of claimed mpg
4. Mitsubishi Outlander PHEV – achieves 42.5% of claimed mpg
5. BMW 2 Series Active Tourer 225xe – achieves 56.4% of claimed mpg
The Mitsubishi Outlander was the most bought PHEV in the UK last year
The Outlander PHEV has proved popular across the continent, already surpassing 100,000 sales
The Mercedes-Benz C-Class C350e plug-in hybrid is that model that misses its advertised mpg by the most, achieving just 36.9% of the claimed figure
This gap between the advertised mpg and what can be achieved by customers can have a serious impact on annual fuel costs.
This being made worse by the fact that fuel prices have risen every single day since the end of March, adding more than 8p to a litre of fuel.
For instance, with petrol current averaging 129.2p per litre, according to PetrolPrices.com, a Mitsubishi Outlander PHEV should cost £354 in fuel costs – based on the claimed mpg – for a driver covering 10,000 miles.
However, HonestJohn.co.uk’s measurement says it will really cost drivers £833 – a difference of £479.
At the opposite end of the performance spectrum, the Lexus GS 450h is the hybrid car that gets closest to its claimed mpg figures.
It achieves 84.2 per cent of its fuel economy claims.
Hybrids closest to their claimed fuel economy figures
1. Lexus GS 450h – achieves 84.2% of claimed mpg
2. Toyota RAV4 Hybrid 2WD – achieves 79.3% of claimed mpg
3. Toyota Yaris 1.5 VVT-I Hybrid – achieves 77.9% of claimed mpg
4. Kia Niro 1.6 GDI Hybrid – achieves 77.4% of claimed mpg
5. Toyota C-HR 1.8 Hybrid – achieves 77.2% of claimed mpg
The Lexus GS450h is the hybrid that gets closest to its official fuel economy figures when tested on the road
Honest John’s managing editor, Daniel Powell, said: ‘This is the most comprehensive study into hybrid fuel economy ever to be carried out.
‘However, while these models are advertised with lofty mpg figures that will appeal to cost conscious drivers, our research shows that on-the-road economy is somewhat different.
‘Given that car buyers are being urged to replace their petrol and diesel cars with new low emission hybrids, we think more needs to be done to ensure drivers get a fair deal when it comes to real mpg.’
While the disparity for hybrid cars is significant, it should shrink when official fuel economy figures are measured under the new World Harmonised Light Vehicles Test Procedure (WLTP) that was introduced last year.
The majority of new car registrations will need to adhere to this test cycle from September 2018.
And while the average hybrid car is some way from its official fuel efficiency figure, they still remain some of the most economical cars on sale to date.
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