Revealed: The Benefits of Transitioning from E5 to E10 Petrol

23 February 2022. 04.10 PM

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With the transition to E10 hitting the UK on the 1st September 2021 comes a whole host of questions around the benefits of the new petrol and its compatibility with lawnmowers and gardening machinery. To help resolve queries regarding the introduction of E10 to Hayter® machines, the experts at Hayter have created a simple guide to avoiding fuel system issues and helping your landscaping projects excel.

What Is E10 Petrol and Why Should You Be Aware of It?

Made up of 90 per cent petroleum-based petrol and 10 per cent ethanol, E10 was initially introduced to reduce carbon emissions as a result of it containing a higher level of renewable fuel. The switch has been estimated to cut CO2 emissions on UK roads by as much as 750,000 tonnes per year according to the Department for Transport (DfT).

Produced from the fermentation of plants such as sugarcane and grains in addition to their by-products, ethanol is an alcohol-based fuel said to be partially atmospherically carbon neutral. As these plants grow, they reportedly absorb more carbon dioxide than will be dispersed into the air during fuel production and combustion, helping to provide a more carbon-neutral alternative to E5 petrol.

E10 Compatibility with Hayter Machines

All current machines using Hayter engines can safely use E10 fuel but not fuel with higher levels of ethanol.

As a general guide machines produced from the following dates are compatible for use of E10 fuel:

Year                     Engine Brand

2000                     Hayter, Toro, Briggs and Stratton, Honda

2011                     Kawasaki

2020                     Kohler

Prior to these dates engines may not be compatible but clarification should always be made via the Engine Operators manual or engine manufacturer.

Engines for Hayter power equipment are not compatible with petrol containing more than 10% ethanol, including E15 and E85, and using either can lead to engine damage and performance issues for your machine.

Mitigating the Risk of Fuel System Issues with E10

When it comes to using E10 fuel with Hayter machinery, it’s essential to remember that ethanol fuel blends absorb water from the atmosphere, potentially causing corrosion of fuel system components. Due to most carburettors and petrol tanks are vented to atmosphere, petrol can easily absorb moisture over time. The rate of oxidisation increases in vented tanks and fuel systems leading to risks of machine failure. However, using fresh petrol of less than 30 days old will minimise this risk, preventing water absorption from becoming an issue.

We recommend purchasing only the amount of fuel that will be used in 30 days, as all petrol steadily deteriorates over time.

Petrol deteriorates over time. Deterioration begins with the most volatile compounds evaporating. Once evaporation reaches a certain point it will be hard/impossible to start the machine. As more compounds evaporate, the petrol will form brown gummy deposits in the system. Given enough time the gummy deposits will become a hard varnish. Gummy deposits and varnish can plug passages in the carburetor preventing the engine from running or causing the engine to run poorly (e.g. surging, lack of power, stalls, etc.). Deposits can also cause the carburetor to leak fuel if they prevent the float needle from sealing  properly.

Another risk factor that can lead to condensation is temperature variance within the storage tank of your fuel. Storing the fuel in dry areas with low humidity is recommended as the ethanol typically absorbs any condensation that forms inside the storage container.

Opting for a quality fuel treatment/stabiliser is always advisable when transitioning to E10 as this minimizes the oxidization rate of the petrol as well as extending the storage life. Be sure to always add the fuel treatment to the container filled with newly purchased fuel on the day of purchase and never directly into the fuel tank of your Hayter mower. There are two types of fuel treatment to consider; one forms a layer over the top of the petrol to significantly reduce the rate of evaporation, also preventing absorption by the fuel. The second type protects the petrol at a molecular level and does not form the same film that the first type of treatment does.

Hayter’s Premium Lawn Mower Fuel Treatment (part number 111-9366) operates at the molecular level, acting as a fuel stabiliser that prevents fuel from oxidising, a cleaning additive that neutralises  and decomposes carbon and gun deposits and a corrosion inhibitor that forms a barrier against rust, oxidization and corrosion. This unique formula complements E10 fuel perfectly, helping to ensure your mowers work to the highest possible standard.

How to Respond if Issues with E10 Petrol Arise

  1. Replace the Fuel Line and Filter

One of our Hayter-approved tips If the carburetor has gummy deposits, varnish or any debris in the bowl you should also replace the fuel line and fuel filter (if present) since these components could contain debris and cause a repeat problem. We strongly recommend you purchase OEM fuel line to ensure compatibility with the engine and the rest of the machine.

Silicone Spray on the Inlet Needle Tip Can Prevent Sticking

When you rebuild a carburetor you may find it leaks when you fuel the machine up for the first time. Applying silicone spray to the float inlet needle during the rebuild process can prevent this.

 Completing this quick and easy step helps to seal the bowl and remove the risk of leaks in minutes.

  1. Consider Replacing Smaller, Inexpensive Carburettors
  2. due to the extremely small passages, and the turns they take, cleaning a carburetor completely can be very difficult. If you find deposits just in the bowl, then cleaning the bowl and main jet may be Internal corrosion indicates the carburetor should be replaced.

Cleaning a Carburettor Safely and Efficiently after Use of E10 Petrol

Before attempting to clean your machinery after using E10 petrol, it’s vital to know that the only substances that should go through carburettor passage are fuel, carburettor cleaner, compressed air and designated cleaning tools.


Make sure you have adequate ventilation, eye protection and gloves that can handle the solvent you are using. Carburetor cleaning chemicals typically produce hazardous fumes, can injure your eyes (and damage spectacle lenses) and may be absorbed through your skin. Read and follow the instructions from the maker of the carburetor cleaner you are using. Do not clean passages with unauthorised tools. Never use fuel nozzle cleaners to clean carburetor passages as they can change the shape and/or size of the passage and harm performance.

If you choose to clean your carburettor after using E10 fuel, opting for an ultrasonic cleaning system is the most effective and time-efficient method.

These systems typically produce few fumes (some use just a solution of soap and water) and do an excellent job of loosening deposits on or in the carburetor. You still need to disassemble the carburetor for cleaning, and use carburetor cleaning spray or compressed air to blow out the passages.   Unfortunately, there is no way to guarantee this will remove all foreign material, and there could be damage (i.e. corrosion) so you may ultimately need to replace the carburetor.

Explore our blog today for more useful guides and machine expertise.