How will E10 petrol affect your STIHL chainsaw

We know there have been many debates about E10 petrol and how it affects petrol tools. E10 petrol became the standard grade in the UK from summer 2021.

Using E10 petrol in your STIHL Chainsaw

E10 petrol contains up to 10% renewable ethanol. This is intended to help reduce CO2 emissions, but we know that some of you have concerns about how this affects your petrol tools. We recommend in all of our owners’ manuals that you should only use high-quality brand-name petrol with a minimum octane rating of 90, but we can reassure you that petrol with an ethanol content of 10% or less, like the new E10 petrol will not cause a problem with your STIHL petrol tool.

In fact, our STIHL M-Tronic engines can still deliver full power when run using petrol with an ethanol content of up to 25% (E25).

However, petrol with an ethanol content of more than 10% can cause running problems in engines with a manually adjustable carburetor so should not be used in such engines.

As with any petrol, we would still recommend not storing your machine with E10 petrol in it, to avoid any blockages in the fuel delivery parts of the tool. We also recommend that you store E10 fuel for no longer than 30 days in order to minimize the degree of fuel segregation. This is where the moisture in the air binds with the ethanol and settles on the bottom of the canister. This can cause running problems and shaking the container does not completely resolve fuel segregation.

In some tools, it may also be necessary to readjust the carburetor to compensate for the changed composition of the fuel. We recommend that you visit a STIHL Approved Dealer for this.

STIHL Motomix is an E10 petrol alternative

Of course, if you are concerned about the use of ethanol in your machines, then you can always consider our premium, patented fuel formula, MotoMix. STIHL MotoMix is completely free from ethanol and has virtually no olefins or aromatic compounds. Emission-wise, this makes it a cleaner, more environmentally-friendly choice than regular fuels, plus it lasts longer so you can store it for up to 5 years, which is handy as MotoMix is available in 200 litre drums!

However, if you still want to use standard petrol, we are happy to reassure you that the new E10 petrol is fine to use in your STIHL petrol tools. You can search for the Instruction Manual for all current STIHL tools and some older versions here if you want to check any fuel recommendations.