Plug-in hybrids ‘costing £500 more a year to fuel than lab tests indicate’

According to an analysis of real data, drivers of plug-in hybrids that are in high demand pay £500 more per year for fuel than the manufacturers suggest. This is largely due to owners charging their cars less often than they should.

According to an analysis by Energy and Climate Intelligence Unit, a climate research organization, laboratory tests suggest that plug-in electric vehicles should cost £560 a yearly. However, real-life data shows that the fuel cost is almost double that amount, at £1,059 a yearly.

The UK has seen PHEV sales grow faster than all-electric car in 2024.

Hybrids combine an internal combustion motor with a battery. This allows them to save fuel and reduce carbon emissions, compared with petrol or diesel only equivalents. Plug-in hybrids can travel up to 40 miles on their battery, which is externally charged via a charging cable.

In theory, the PHEV battery should be used almost for every trip: 94% in England are less than 25 miles. In reality, owners don’t always plug in and instead use their internal combustion engines.

In March, the European Commission of the EU found that in real life carbon emissions for PHEVs registered after 2021 are on average three times higher in comparison to laboratory tests. “This is largely due to them not being charged or driven as often as they were assumed”.

EU figures confirm that plug-in hybrids are still able to save significant amounts of fuel compared to standard petrol cars. The ECIU determined that petrol cars cost £1,652 a yearly to fuel. This was 56% more expensive than PHEVs and four times as much as driving an electric vehicle, which uses far more energy. The ECIU reported that electric car owners pay an average of £388 a month to charge their cars if they do it at home. The costs would be higher if you depend on public charging stations.

Colin Walker, head of the ECIU’s transport division, stated that plug-in hybrid vehicles still receive a “petrol premium” of hundreds of pounds per year.

He said: “It is important that [potential car purchasers] are aware that, according the data, PHEVs not only produce 350% MORE CO 2 than what their manufacturers claim but they will also not deliver fuel savings as impressive as the manufacturer claims,” he added.

Ben Nelmes is the chief executive at New AutoMotive. A think tank that advocates for the adoption of electric vehicles, and argues in favor of PHEVs. He said the tightening of emissions regulations was a factor behind the increase of PHEV sales in Europe. He said that the data from the commission showed hybrids “failing in the real-world”.

He said that this highlights the dangers in passing laws to try and reduce the environmental impact from fossil-fueled vehicles. This approach will always be based on tests that do not reflect real-world driving, or on unrealistic claims made by manufacturers. The UK avoids this problem in a sensible way by switching to a regulatory strategy that is focused on eliminating tailpipe emissions and a complete break from the internal combustion engines.

The UK’s Zero Emission Vehicle (ZEV mandate) will force manufacturers to sell an increasing proportion electric cars, until the sale of new petrol or diesel engines is banned in 2035.