During summer 2021 the fuel companies and the government have changed the ethanol content of standard 95 octane unleaded petrol sold at the pumps from 5% ethanol content to 10% ethanol content. They will still offer the lower 5% ethanol content fuel but only in the more premium grade super unleaded fuel. These will be identifiable on the pump handle with E10 or E5 labelling (as shown on the top image).
Ethanol effects in garden machinery is nothing new and even the 5% ethanol content has been causing issues in the past few years as the ethanol in the fuel goes stale (like milk), but the 10% rise in ethanol content in unleaded pump fuel could cause the effects of unleaded fuel going stale to increase and cause the damage to increase on fuel lines and carburettor components like rubber gaskets, diaphragms and ethanol deposits will block the jets up inside the carburettor. Ethanol will also degrade the aluminium casting of a metal style carburettor.
This fuel change will also affect other small petrol engine machinery like outboard boat engines, petrol generators, construction equipment using petrol engines and classic cars, old motorbikes and scooters and other vehicle petrol engines built before the year 2000. Most new small engines built after the year 2000 fitted to garden machinery, generators and construction equipment will run on the E10 fuel, but manufacturers recommend the new standard E10 fuel isn’t stored or left in the fuel system of a engine for more than “30 days without a fuel stabiliser” and the E5 super unleaded isn’t stored or left in the fuel system of a engine for “90 days without a fuel stabiliser”.
If you are using your garden machinery or other equipment for daily use and long running periods (contractor, forestry and grounds maintenance use), E10 or E5 can be used, but it is still recommended by the manufacturers to use a suitable fuel stabiliser or oils containing fuel stabilisers (two stroke machinery oils) to keep your equipment running at its top performance and to reduce machinery downtime.
To keep your petrol-powered garden machinery operating at its best and avoid issues with ethanol you can use the following items.