What Is E10 Fuel?


The standard grade for petrol in the UK has now changed from E5 to E10. E5 fuel contains 5% renewable ethanol and is still available from petrol stations but will now be classed as the "Super" grade fuel. E10 petrol contains up to 10% renewable ethanol, which will help to reduce carbon dioxide (CO2) emissions associated with petrol vehicles and tackle climate change. 

What Is Ethanol?


Ethanol is an alcohol-based fuel which is produced from the fermentation of a range of plants, including sugarcane and grains, along with their by-products. Unlike regular unleaded petrol, ethanol fuel is said to be partially atmospherically carbon-neutral. This is said because as the plants that will become ethanol grow, they reportedly absorb more carbon dioxide than what will be released into the air during fuel production and combustion. This partially offsets the greenhouse gas emissions produced by its production and use.

The trouble with ethanol as a fuel is that its hygroscopic, this means it attracts and mixes with moisture in the air, causing corrosion to metal components in the fuel system. If enough water is absorbed, the ethanol and water will settle out of the petrol/oil mixture and settle to the bottom of the machines fuel tank. The layer of petrol left floating on top has a lower octane level than the original ethanol petrol blend, which can result in unstable engine operation, power loss and major engine failures.

Since the fuel is often drawn from the bottom of the fuel tank, the engine is drawing in a mixture of ethanol and water with no petrol and therefore no lubricating oil. This ethanol/water mix cannot easily pass through the fuel system, this can result in hard starting, unsafe high idle speeds, stalling, and can ultimately lead to engine damage or fuel system failure.

How Will This Affect Your Power Tools?

Due to the higher ethanol content there have been concerns as to how this new standard fuel will affect your petrol power tools. Different manufacturers have provided information on how this fuel may affect performance and the guidelines for using this new standard petrol. Follow the links below to see this information : 

Stihl E10 Fuel Statement 

Husqvarna E10 Fuel Guidelines - PDF

Honda E10 Fuel Statement

Honda E10 Fuel Guidelines - PDF



We recommend that you follow the guidance given by the manufacturer of your power tools. If you are concerned by the Ethanol content in the new grade of petrol there are Alkalyte based fuels available which don't contain any. Stihl's Motomix and Husqvarna's XP 2T are examples of this fuel which have an incredibly long shelf life and contain the highest grade of two stroke oil available from each manufacturer.

Honda Fuel stabiliser will additonally help to stop the fuel from deterioating when added to the petrol when it is fresh, especially if being stored for longer than a 30 day period. Fuel stabiliser doesn't renew stale fuel but it helps to prevent varnishing and potential gummy deposits being left on the metallic and sensitive elements of the engine.

Additional Information

If you would like to know more about E10 Fuel then head on over to the Government website which details the reasons behind the change and offers additional guidance. 

E10 petrol explained - GOV.UK (www.gov.uk)

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