Since September 2021, the standard petrol at UK pumps switched from E5 to E10. But what does that actually mean?
What Do E10 and E5 Mean?
The "E" stands for ethanol, and the number is the percentage:
- E10 = up to 10% ethanol, 90% petrol
- E5 = up to 5% ethanol, 95% petrol
Can Your Car Use E10?
Almost certainly yes. Around 95% of petrol cars on UK roads are compatible. All cars built since 2011 are required to be E10 compatible.
Check the Government's official compatibility checker if you're unsure.
What If Your Car Isn't Compatible?
E5 petrol is still available as "super unleaded" or "premium unleaded" at most stations. It's more expensive but safe for older vehicles.
Does E10 Affect Fuel Economy?
Yes, slightly. E10 has roughly 2-3% less energy per litre than E5, translating to approximately 1-2% worse fuel economy.
Is E5 Premium Worth the Extra Cost?
The maths doesn't work for most drivers. E5 costs 10-15p more per litre but only gives 2% better economy. E10 is still more economical overall.
Key Takeaways
- E10 is fine for 95% of cars
- E5 is still available as super unleaded
- E10 gives slightly worse economy but is cheaper overall