E10 fuel was introduced in the UK on 1 September 2021 as a more sustainable form of petrol as compared to the previous E5 petrol that was available at petrol stations. Almost a year after this change in the UK, the Department of Transport has announced that the same change will be observed in Northern Ireland, where drivers still use E5 petrol to fuel up their cars, from 1 November 2022 onwards.

Simply put, fuel containing 10 per cent of bioethanol is called E10 or ‘premium’ petrol.
E10 petrol is a biofuel used in transportation. It contains 10 per cent renewable ethanol instead of the previous standard petrol grade – E5 or super grade petrol – which contains up to five per cent ethanol. E10 fuel is widely used in various countries within Europe, such as Finland, France, Germany and Belgium, and outside Europe, including Australia. Related: Learn more about different fuel types, and which one is right for you

The main difference between is E5 and E10 fuel is that E5 contains only five per cent ethanol while E10 contains 10% ethanol and 90% gasoline.
Another difference between E5 and E10 is how they are produced - ethanol is a renewable, colourless alcohol that is made from agricultural sources such as sugar beets. E10’s higher volume of ethanol means the reliance on fossil fuels is reduced as more plant materials are to produce the ethanol. Ethanol can be easily sourced from processed corn which means that E10 fuel plays a greater role in supporting businesses in the farming and manufacturing sector. Also, when ethanol is produced, it produces valuable by-products such as high protein animal feed and stored CO2, which can be used by various industries and can help reduce the need to import these products. Ethanol is also non-toxic and renewable. The higher percentage of ethanol in E10 helps reduce a vehicle’s CO2 emissions as ethanol absorbs CO2 as it’s produced during fuel combustion.

It’s usually cheaper to fill your car with E10 petrol than with E5, due to its wide availability across the country. Since E10 became the standard petrol grade, however, this doesn’t mean that it’s lower quality.
The Department for Transport’s impact assessment estimated the reduction in petrol costs to be by 0.2 pence per litre. However, a shift from E5 to E10 may increase the overall fuelling costs for petrol cars by 1.6 per cent as the energy content of E10 fuel is less than that of E5 which can slightly reduce your car’s fuel economy. The reduced fuel economy would increase the need to refuel and thus, motorists would end up buying more litres of fuel - this would slightly increase the total amount spent on refuelling overtime. Related: Fuel-efficient driving tips to reduce car emissions

While most cars are compatible with E10 fuel, some cars manufactured before 2011 may not be compatible with E10 and require you to use E5 petrol instead.
You can do a quick and easy E10 compatibility check on gov.uk for free if you’re unsure about whether your car’s compatible with E10 fuel grade or not. You can use this E10 petrol check service to confirm its compatibility with vans, motorcycles and mopeds. You can also check if your vehicle is compatible with E10 petrol by checking the user manual or asking the manufacturer.

E10 petrol: classic cars

E10 fuel may not be compatible with some of the classic cars and older cars, as well as cars using a carburettor. Again, you can use gov.uk’s E10 checker to find out whether your car can run on E10 fuel or not.

If your vehicle is listed as incompatible and you use E10 fuel instead of E5 you won’t require any immediate action like draining out the fuel, which would be the case if you used diesel instead of petrol (or vice versa).
Simply check compatibility to make sure that E10 fuel is okay for your car and use the right fuel next time. Filling stations clearly label the petrol as E5 or E10 on both the petrol dispenser and nozzle so that you use the right fuel for your car according to compatibility. Likewise, if you're out and about and the filling station you stop at doesn't stock E10 or none is available (as you may find in some more remote locations) you don't need to worry too much about filling up with E5 every once in a while.

The apparent risks of running an older car that doesn't appear on the Government list of E10-compliant vehicles have been somewhat overstated. The relatively small change in the proportion of ethanol in unleaded shouldn't cause too many problems, even in older cars.
Many countries have been using E10 for years, and a study commissioned by the US military and Department of Energy as far back as 1981 concluded there was no additional wear and tear to the engine from using E10. While it's true the higher ethanol content does increase the fuel's tendency to absorb condensation in the system, and that could conceivably increase corrosion in metal components like fuel lines and tanks, this would happen anyway in older cars and be considered 'service items' anyway, ditto seals, rubber tubes and other components in the fuel system. The best way to avoid potential issues would be to use your car as regularly as possible to avoid condensation, corrosion and other issues.

Vehicle owners can still use E5 fuel if they wish to.
Filling stations still sell E5 as approximately five per cent of cars in the UK aren’t compatible with E10 according to gov.uk. Although, the number of E10 compliant cars will only increase as the older cars become redundant and get replaced with newer ones.

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