E10 petrol: is an older car compatible?

Most petrol cars on the road can use E10, the standard grade at UK filling stations. The Department for Transport says all new cars made since 2011 are compatible, and most cars made since the late 1990s are too. Some cars from the early 2000s and older are not, and classic cars should stay on E5 super unleaded. If you are buying an older petrol car, check it with the GOV.UK E10 checker before you buy, so you know what to put in the tank and what that will cost you.

What E10 is

E10 is petrol blended with up to 10% renewable ethanol. The grade it replaced as standard, E5, contains no more than 5%. The government says the switch to E10 could cut transport CO2 emissions by 750,000 tonnes a year.

Standard grade (95 octane) petrol became E10 in Great Britain in September 2021 and in Northern Ireland in November 2022.

Which cars can use E10

According to the government's guidance:

• All new cars manufactured since 2011 are compatible with E10.
• Most cars and motorcycles made since the late 1990s are approved for it too.
• Some vehicles from the early 2000s may not be compatible, and this is where you need to check.
• Classic and older vehicles are often not compatible, and owners are advised to use E5.

You cannot tell from the age alone. Two cars from the same year can differ, because compatibility depends on the engine and the fuel system materials. That is why the checker matters more than the date.

How to check a car

1. Use the GOV.UK checker. The Check if your vehicle can use E10 petrol service asks for the manufacturer, and may also need the model, engine size and year of manufacture, which are on the V5C logbook. It does not need a registration number.
2. Look in the handbook. It usually states the fuels the car can use.
3. Ask the manufacturer or a main dealer if the checker does not list the car or you are unsure.
4. Ask a specialist for a classic, a modified car or a car with a rebuilt fuel system.

When you buy an older petrol car, ask the seller what fuel they have been using and whether any fuel lines, seals or the fuel pump have been replaced. If the car needs E5, factor in the extra cost of super unleaded for every fill-up.

Where to buy E5

E5 is still sold as the "super" grade, petrol of 97 octane or more with no more than 5% ethanol. The government guidance says E5 will remain available at filling stations that sell two grades of petrol. Not every small filling station sells two grades, so if your car needs E5, note where you can get it on your usual routes.

If you put E10 in a car that cannot use it

Do not panic. The government's guidance says that using a single tank of E10 in a vehicle that is not compatible should not be a major problem. Fill up with E5 next time.

What to avoid is using E10 for a long time in a car that is not compatible. The guidance says prolonged use may cause harm and is not recommended. The concern is the effect of ethanol on some older seals, plastics and metals in fuel systems.

This is different from putting petrol in a diesel or diesel in a petrol car. That is a misfuelling problem: do not start the engine, and call for help.

Classic and stored cars

If you own or are buying a classic car, keep using E5 unless the manufacturer or a specialist confirms it can use E10. If a car will stand for months, ask the owners' club or a specialist about fuel and storage.

Cars over 40 years old can qualify for the historic vehicle tax class, and many are exempt from the MOT. Our guides to the historic vehicle tax exemption and the MOT exemption for 40-year-old cars explain the rules.

E10 and buying a used car

For most used petrol cars, E10 makes no difference at all to the buying decision. For an older petrol car from the early 2000s or before, add one check to your list:

• run the make and model through the GOV.UK E10 checker before you view it;
• if it needs E5, work out the running cost with super unleaded prices;
• ask the seller about fuel system work and see the invoices;
• see the car and ask a mechanic if it runs roughly or smells of fuel.

Our used car buying checklist covers the rest of the checks.

Frequently asked questions

Can my car use E10 petrol?

If it was made in 2011 or later, yes. If it is older, most cars from the late 1990s on can, but some from the early 2000s cannot. Check the make and model on the GOV.UK E10 checker.

What happens if I put E10 in a car that is not compatible?

One tank should not be a major problem, according to the government's guidance. Fill up with E5 next time. Long-term use in a car that is not compatible may cause harm.

Is E5 petrol still available?

Yes. E5 is sold as the super grade at filling stations that sell two grades of petrol.

Does E10 affect fuel economy?

The government guidance says E10 can slightly reduce fuel economy, by around 1%, and that this is unlikely to be noticeable in everyday driving.

Should classic cars use E10?

Usually not. The government guidance says classic and older vehicles are often not compatible, so keep using E5 unless the manufacturer or a specialist says otherwise.