E10 Petrol Explained: What It Is and Is Your Car Compatible?

Summary

• E10 contains 10% ethanol: It replaced E5 as the standard petrol in September 2021.
• Most cars built after 2011 are compatible: Over 95% of petrol cars can use E10 with no issues.
• E10 gives slightly lower fuel economy: About 1–2% less mpg than E5. Use our fuel finder to find the best prices.

If you've filled up at a petrol station recently, you may have noticed the E10 label on the pump. Here's what it means for you and your car.

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What Is E10 Petrol?

E10 is standard unleaded petrol that contains up to 10% bioethanol. Ethanol is made from crops like wheat and sugar beet.

Previously, UK petrol was E5 — containing up to 5% ethanol. The switch to E10 was made to reduce CO2 emissions.

• E10 reduces CO2 by about 750,000 tonnes per year — the same as taking 350,000 cars off the road.
• E5 (super unleaded) is still available at most stations for incompatible cars.

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Is My Car Compatible with E10?

Most cars are fine with E10. The general rules:

• Cars built after 2011: Almost all are compatible.
• Cars built 2000–2011: Most are compatible, but check with the manufacturer.
• Cars built before 2000: Many are NOT compatible. Ethanol can damage older rubber seals, hoses, and fuel system components.

Check the official government tool at gov.uk/check-vehicle-compatibility-e10.

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What If My Car Can't Use E10?

If your car isn't compatible:

• Use E5 (super unleaded): This is still available at most petrol stations. It costs 10–15p more per litre.
• One tankful won't cause damage: If you accidentally fill up with E10, don't panic. One tank is unlikely to cause problems. Just switch back to E5 for the next fill.
• Long-term E10 use in incompatible cars: Can corrode fuel lines, seals, and injectors. Avoid it.

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Does E10 Affect Fuel Economy?

E10 contains slightly less energy than E5. In practice:

• About 1–2% reduction in miles per gallon
• On a 50-litre tank, that's roughly 5–10 fewer miles per fill
• The cost difference is minimal — about £10–£20 per year for average drivers

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E10 and Classic Cars

Classic car owners need to be especially careful:

• Cars built before the mid-1990s often have rubber and cork components that ethanol degrades.
• Carburettor-fed engines can struggle with higher ethanol content.
• Use E5 (super unleaded) or add an ethanol-compatible fuel additive.

If in doubt, use E5 super unleaded. It costs more per litre but protects older fuel systems from ethanol damage.

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Key Facts About E10

Question	Answer
When did E10 become standard?	September 2021
Is E5 still available?	Yes — as super unleaded at most stations
Does E10 damage modern cars?	No — 95%+ of petrol cars are fully compatible
Is E10 cheaper?	Yes — about 10–15p/litre less than E5 super

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