Fuelling the Future: E10 Fuel Changes

Fuelling the Future: E10 Fuel Changes
26th March 2021 Team CSF

Fuelling the Future: E10 Fuel Changes

What are the changes?

From 1st September 2021, all 95-octane petrol on sale will be E10 grade, meaning that there will be up to 10% ethanol present in the fuel. As ethanol is renewable, produced from crops rather than oil, it is seen as a greener alternative to more traditional fuels.

Why does it matter?

For most modern cars, typically manufactured after 2000, the introduction of E10 isn’t an issue. However, the RAC estimates that as many as 600,000 vehicles in the UK are not compatible with E10. Classic and historic vehicles would fall within this, and for these sectors, there are two main areas of concern.


According to the FBVHC the long-term storage of E10, for example during winter storage, can lead to corrosion in historic vehicle fuel systems.

The Royal Society of Chemistry published a paper by researchers in Malaysia and Saudi Arabia which explains why; “bioethanol attracts more water from the environment because it is hygroscopic in nature” meaning that it attracts moisture from the air. Therefore, it can “cause a corrosive effect on engine components such as fuel injector and electric fuel pump” and metal fuel tanks if left for a long period of time.

Material Compatibility

Some plastic and rubber components used in older cars are incompatible with E10, with Auto Express reporting that fuel lines have perished prematurely posing a fire risk to “classic cars and their owners”. This is confirmed by the Department for Transport press release from the 25th February that states “higher blends of ethanol can cause corrosion of some rubbers and alloys used in the engine and fuel systems of some older vehicles”.

What can be done?

Very simply – user super unleaded. Higher octane 97+ fuels will remain E5 grade and according to the AA fuels which contain “up to 5% Ethanol in petrol is considered not to cause any compatibility issues with car fuel systems”. The government has stated that the availability of these “protection grade” fuels will be reviewed in five years.

“Such a review will examine if there’s a viable and widely available alternative to ensure suitable low-ethanol fuel remains available for older vehicles and other petrol-powered machinery that require it. We would like to reassure owners of such vehicles or equipment that, without such an alternative becoming available, it’s highly likely the E5 protection grade would continue to apply”

Additionally, the FBHVC has approved a number of products that inhibit the corrosive elements of E10 which can be found at https://www.fbhvc.co.uk/fuels.


For now, there seems to be no need to panic. The availability of suitable fuels to power our classic and historic vehicles is still very much in the mainstream. Four-star fuel was removed from the majority of forecourts twenty years ago; however, it is still available to purchase from a small number of retailers even today.  As such, we’re confident that the future of the classic car sector will be kept firing on all cylinders for generations to come.