E10 or E5 Petrol: Which Should You Buy?

Updated 7 Nov 2026

E10 is the standard unleaded in Great Britain and E5 is the dearer "super" grade. What the difference is, which cars need E5, and what it costs per tank today.

Today E10 unleaded averages 171.0p a litre at the stations we track, and E5 (usually sold as super unleaded) 190.3p, a difference of 19.3p. On a 50-litre fill-up, E5 costs about £9.63 more.

What the numbers mean

The number is the maximum share of bioethanol: E10 can contain up to 10%, E5 up to 5%. E10 became the standard 95-octane petrol in Great Britain in September 2021 to cut CO₂ emissions. E5 is still sold, mostly as the higher-octane super grade.

Can your car use E10?

Almost every petrol car built since 2011 can, and so can most cars from the late 1990s on. Some older and classic vehicles, and a few specific models, should stay on E5 because ethanol can damage older seals and fuel lines. The government’s online E10 vehicle checker tells you for your make and model. If you put E10 in a car that should not have it once, the car will still run; just fill up with E5 next time.

Is E5 worth it if your car takes E10?

• Ethanol contains a little less energy than petrol, so E10 can reduce fuel economy by around 1%. At today’s prices that is far less than the price gap to E5.
• Performance cars that ask for 97 or 98 octane in the handbook should use super unleaded.
• For everyday cars designed for 95 octane, E10 is the cheaper choice.

Diesel

Diesel averages 198.3p a litre today. Standard diesel in the UK contains up to 7% biodiesel (B7) and suits all diesel cars.

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