We know there are many debates taking place right now about E10 petrol and how it will affect petrol tools. According to www.gov.uk, E10 petrol will become the standard grade in the UK from summer 2021.
E10 petrol will contain up to 10% renewable ethanol. This is intended to help reduce CO2 emissions, but we know that some of you may have concerns about how this will affect your petrol tools. Stihl recommend in all of their 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, the 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. 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.