Fuel that is more environmentally friendly may actually pose more issues for some drivers, experts have warned.
The new "climate friendly" E10 fuel could lead to "worse problems" for drivers because it is less "energy dense", meaning motorists will have to use more to cover similar distances.
The fuel, that was introduced in September, has won admirers because it contains a higher percentage of renewable fuel - bioethanol.
This means it is better for the environment due to the lower levels of carbon emissions.
But motoring YouTube channel Number 27 has warned that E10 may have "far worse problems" that could affect all petrol car users.
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The issue, they say, with it being less "energy dense" means that motorists may have to top up more often, leading to additional costs.
In the video, the presenter says: “I need to talk to you about something pretty shocking I've just found out about E10 fuel.
“And it has absolutely nothing to do with the fact it might damage old classics.
“No, there is a far worse problem with using E10.
“It affects every single car on the road which uses petrol whether it is one of the oldest or the very newest car that’s out.”
He added: “E10 causes an increase in fuel consumption for any car that's using it. Ethanol is less energy-dense than unleaded fuel.
“So that means that because it has this lower energy density you have to use more and therefore your fuel consumption in your car will go up.
“You’re not going to lose any power because your car's computer will alter the air-fuel balance to make up for that loss of energy density.
“But your fuel consumption will go up. I really couldn't believe it.”
The Department for Transport's Introducing E10 petrol study confirmed drivers would experience lower fuel economy under the new E10 grade.
They confirmed fuel economy may drop by up to two per cent using the new compound.
But they said this was ultimately down to the “driving style” of motorists.
The revelation came after concerns were raised by a quarter of private individuals in relation to fuel economy in the consultation.
Drivers questioned about the changes warned this could “mitigate emissions benefits” and could have a “cost impact”.
The DfT said: “We have considered the impact on fuel economy and decreasing MPG, which is due to the lower energy density of ethanol compared with fossil petrol when developing our proposals.
“Analysis based on average calorific values of the two products suggests fuel economy could reduce by between one and two per cent.
“However, the impact will vary based on driving style and refinements in fuel blending by suppliers.”
According to the RAC, the US Energy Information Administration (EIA) claims the energy content of ethanol is around 33 per cent lower than unleaded.
This means vehicle fuel economy may reduce by around three per cent when using the new fuel.
A number of drivers have reported suffering from fuel efficiency problems when using the new fuel.
Some Express readers have even complained of receiving up to 4mpg less since the changes.
