A new type of unleaded petrol has been introduced to the UK market, but what is it? Here's your quick guide to the essential information about E10.

 What's new?

In the last few years, petrol and diesel fuel in the UK has featured a percentage of biofuel in its makeup. Since 2018 you will have seen additional labels on the pumps at UK fuel forecourts: E5 and B7. These indicate the percentage of biofuel in the mixture; E5 meaning 5% ethanol and B7 meaning 7% biodiesel. As of September 1st 2021, the amount of ethanol in standard 95 octane UK petrol has increased to 10% thus bringing about the new E10 fuel. 

Ethanol is a renewable synthetic fuel which is made from crops. Using plant-based fuels helps to reduce carbon emissions as the crops absorb carbon whilst they grow. Ethanol has been used in racing fuels for a while now, with Formula 1 and the FIA World Endurance Championship allowing higher concentrations of biofuel to be used in the cars. Switching from E5 to E10 petrol could reduce transport CO2 emissions by 750,000 tonnes per year. To give it some context, that is the same weight as 371,287 new S-Class Saloons. 

It has also been the standard of fuel used since 2016 in other markets and is the fuel used for emissions testing. Super unleaded (rated at 97 octane and above) will remain on sale as an E5 fuel.

Can my Mercedes-Benz or smart use E10?

All cars built from 2011 onwards have been made to be compatible with the new E10 fuel. Mercedes-Benz had been ahead of the curve for a while so even if your car is a pre-2011 model it will be compatible with the fuel unless:

•      Your car is a 203 generation C-Class C 200 CGI built between 2002 and 2005

•      Your car is a 209 generation CLK-Class CLK 200 CGI built between 2002 and 2005

•      Your engine features a carburettor rather than fuel injection

•      Your car is not equipped with a three-way catalyst or was retrofitted with a three-way catalyst

All smart petrol models are certified to run E10 fuel. 

If you are unsure, you can check your car's compatibility by using the E10 Checker on the Government website. Here you can also check the compatibility of other manufacturer's products with E10. 

What if my car can only use E5 fuel?

The ethanol content of super unleaded is not changing. Petrol rated at 97 octane and above will remain on sale as an E5 fuel.

What could happen to an incompatible car?

A car that is not certified to use E10 will not explode instantaneously but prolonged use of the higher ethanol concentrated fuel may cause damage to the fuel pumps, lines, filters and carburettors. E10 may work its way through rubber components and seals in older engines found in classic models. If in doubt with your classic Mercedes-Benz, use E5.

Is diesel changing?

No. Diesel will remain at the B7 grade for the foreseeable future.

Will E10 cost more?

No. Think of it as the standard grade of petrol becoming E10 rather than a new type of super unleaded being introduced. 

Where can I check my car's E10 compatibility?

The Government E10 checker allows you to check the compatibility and exclusions for E10 fuel.