Unleaded petrol is changing to E10, all you need to know

June 25, 2021
Unleaded petrol is changing to E10, all you need to know

Unleaded petrol changing from E5 to E10

As of 1st September 2021, forecourts across the UK will be required by law to sell E10 unleaded petrol as their standard fuel. The E10 fuel uses 10% of bioethanol in the fuel mixture delivered out of the pumps, compared to the current grading of E10 which uses just 5% bioethanol in the fuel mix. The new law/changes have no effect and make no changes on diesel fuels in the UK.

What is Bioethanol?

Bioethanol is a renewable fuel that is man made. Bioethanol is created by a fermentation process of a wide range of crops including sugar beet, wheat, corn and even some food waste!

Why the change from E5 to E10?

By increasing the % of Bioethanol in the fuel mixture from the current 5% up to the new mixture of 10% it will decrease the amount of fossil fuel burnt by motor vehicles. Just this simple change of 5% is expected to bring annual savings of up to 750,000 tonnes of CO2 emissions from vehicles, this would be the same as taking a staggering 350,000 vehicles off the road each year.

Sounds too good to be true? right?

Some may say there must be a catch or a downside to such a change. In real terms, the vast vast majority of drivers will not notice any difference other than the E10 badge on the pump. There is likely to be an incredibly small drop in MPG fuel economy values on most cars as Bioethanol is less energy dense than standard petrol but the latest DFT predictions are showing just a 1% drop in economy. Given that other factors such as driving styles, incorrectly inflated tyres, air conditioning and poorly maintained cars have far greater effect on fuel economy, for many the 1% difference is probably unnoticeable.

Are all cars compatible with E10?

Since 2011, all cars sold within the UK are compatible with the E10 fuel, it is worth noting that manufactures have been adhering to the E10 compatibility long before the 2011 limit came into effect. Over 95% of cars built since 1990 will work just fine with the E10 fuel.

There are some significant/popular exemptions that cannot use the E10 fuel, namely the early VW models with FSI engines. Some of these models include MK4 and MK5 VW Golfs, some VW Polos and VW Touran people carriers.

If your car was built before 2011, chances are you will be fine with E10 but the government has a handy E10 fuel checker which can be found by clicking the link below.

Check if your vehicle can run on E10 petrol - GOV.UK (www.gov.uk)

Can I still buy E5 fuel?

In short, yes! E5 will still be sold in many, if not all forecourts in the form of 'premium' fuels. These premium fuels are often sold as 'Supreme', 'High Grade' or 'High Octane' mixes and generally contain a greater Octane rating as well as the 5% Bioethanol mixture. They do however attract a much higher price premium over the standard E10 petrol being sold. These premium fuels are largely aimed at high performance or specialist cars but are also the alternative to any vehicle not compatible with E10.

Does this effect emissions?

In short, E10 is designed to reduced CO2 emissions only and will have very little, or no effect on emissions that effect air quality & pollution, or public health.

Whilst we know that this will save a lot of CO2 each year, which is fantastic, the effect it will have on other areas is likely to be very little. With the higher percentage of ethanol in the system it is unlikely to have any effect on air pollution with NOx and particulate matter being main contributors, that remain uneffected.

It's also worth noting that the E10 fuel won't have any impact on emissions and congestion charges such as the LEZ, ULEZ or Birmingham CAZ.

Classic cars and the use of E10 fuel

Many classic vehicles won't be listed in the online E10 checking tools and limited data or knowledge will be available for them. Many of the classic vehicle manufactures aren't even trading and thus getting reliable data is going to be difficult.

In these instances, the recommendation is to use E5 premium fuels to avoid the possibility of any damage or issues down the line. Local clubs, enthusiast groups and specialists are the best sources for information on whether classic vehicles are compatible with the E10 fuel.

I've put E10 into a car that's not compatible, what next?

When this scenario happens then don't panic! Unlike putting in the wrong fuel which can have catastrophic effects, putting E10 into a vehicle that's not compatible isn't a real issue. Simply top up the tank with E5 at your next petrol top up. Short term use of E10 is unlikely to have any effect, the real issues and problems occur with long term use of E10 in a vehicle not compatible.

Can I mix E5 and E10 petrol?

Yes, there is no reason why you can't mix the two fuels together if your vehicle can run on E10. If for any reason E5 is the only option, or you wish to run every other fill with E5 as a 'boost' then this won't cause any issues. If your vehicle isn't compatible with E10 then you shouldn't use E10, although an accident fill can be topped up with E5 without any long term effects.

Other Engines

Please keep other mechanic engines in mind when sourcing E10 and E5 fuel. Areas to consider include petrol powered machinery (lawnmowers, chainsaws, strimmers etc), ride on machine such as Lawnmowers, Gators etc, petrol generators, petrol pumps, boat outboard motors etc. If in any doubt please always use E5 until specific data is available to say they are compatible with E10 fuel.

How will I know E5 from E10 petrol?

The fuel stations in the UK should label the fuels correctly and clearly. The standard label is the petrol name in a black circle and will look like the image below. This should be clearly marked on the pumps. You will likely find that E10 will be sold as 'Unleaded Petrol' and the E5 will be sold as a premium fuel such as 'Supreme' or 'High Octane'. Newer vehicles, namely those from 2019 onwards are likely to have these labels on the fuel cap or near the fuel filler area to show which fuel they are compatible with.

E10 and E5 Petrol Labels