What Is E10 Petrol and Can My Car Use It?
E10 petrol became the standard grade of unleaded fuel at UK forecourts in September 2021. If you've wondered what the "E10" label on the pump means — and whether your car can safely use it — this guide covers everything you need to know.
What Is E10 Petrol?
E10 is a petrol blend containing up to 10% bioethanol, derived from materials including grains, sugars, and waste wood. The remaining 90% is standard unleaded petrol.
The "E" stands for ethanol, and the number indicates the maximum percentage by volume. The previous standard — E5 — contained up to 5% ethanol.
The UK government mandated the switch to E10 as part of its commitment to reduce carbon emissions from road transport. According to gov.uk, E10 fuel can cut CO₂ emissions by around 750,000 tonnes per year — the equivalent of taking 350,000 cars off the road.
Why Did the UK Switch to E10?
The shift to E10 was driven by the Renewable Transport Fuel Obligation (RTFO), which requires fuel suppliers to blend a proportion of renewable fuel into the petrol and diesel they sell.
Bioethanol burns more cleanly than pure fossil-fuel petrol, reducing some tailpipe emissions. The RAC noted at the time of the switch that E10 is already the standard fuel grade across much of Europe and the United States.
There is a trade-off: ethanol contains less energy per litre than petrol, so E10 can reduce fuel economy by around 1–3% compared to E5 in most vehicles.
Is My Car Compatible with E10 Petrol?
The vast majority of petrol cars on UK roads are fully compatible with E10. According to gov.uk, all cars manufactured from 2011 onwards are E10 compatible, as are most vehicles made after 2000.
Use the official gov.uk E10 petrol compatibility checker to verify your specific make, model, and year.
Vehicles That May NOT Be Compatible
Some older or specialist vehicles are not E10 compatible, including:
- Cars built before 2000 (many classic and vintage vehicles)
- Some models from 2000–2010 — check the official tool
- Certain motorcycles and mopeds, particularly older models
- Some small engines — lawnmowers, generators, outboard motors
- A small number of cherished or historic vehicles with rubber seals and fuel system components that can degrade with higher ethanol content
If your vehicle is not E10 compatible, continue using E5, which remains available as "Super Unleaded" (97+ octane) at most forecourts.
E10 vs E5: What's the Difference at the Pump?
| | E10 | E5 (Super Unleaded) | |---|---|---| | Ethanol content | Up to 10% | Up to 5% | | Octane rating | 95 RON | 97–99 RON | | Typical price | Lower | Higher (premium grade) | | Availability | Standard grade everywhere | Most forecourts | | CO₂ impact | Lower than E5 | Higher than E10 |
E5 Super Unleaded is typically 5–10p per litre more expensive than standard E10. For incompatible vehicles, this is a necessary cost — not an upgrade choice.
Does E10 Affect Fuel Economy?
Yes, modestly. Because ethanol has lower energy density than petrol, E10 can reduce fuel efficiency by 1–3% compared to E5.
In practice, for a car averaging 40mpg, this might mean losing roughly 0.5–1mpg. The AA has noted this effect is unlikely to be noticeable for most drivers in everyday use.
If you're doing a long motorway run and want to maximise range, Super Unleaded E5 may eke out slightly more miles per tank — but the price premium usually outweighs the efficiency gain.
What Happens If I Put E10 in an Incompatible Car?
A single fill-up of E10 in an incompatible vehicle is unlikely to cause immediate damage. However, repeated use can cause problems over time, including:
- Degradation of rubber seals, hoses, and fuel lines
- Corrosion of some metal fuel system components
- Starting and running issues in vehicles with carburettors
If you've accidentally used E10 in an incompatible vehicle, the AA recommends topping up with E5 Super Unleaded to dilute the blend, and monitoring for any symptoms.
Practical Takeaways for UK Drivers
- Check compatibility at gov.uk before assuming E10 is fine for your vehicle
- Most cars from 2011 onwards are compatible — standard E10 is safe to use
- Incompatible vehicles should use E5 Super Unleaded (97+ octane, available at most forecourts)
- E10 gives a small CO₂ benefit but a minor fuel economy penalty
- E5 costs roughly 5–10p per litre more — factor this in if you're budgeting fuel costs
To check current E5 and E10 prices at forecourts near you, compare local fuel prices across thousands of UK stations in real time.
Frequently Asked Questions
What is E10 petrol?
E10 is the standard grade of unleaded petrol in the UK, containing up to 10% bioethanol blended with 90% conventional petrol. It replaced E5 (5% ethanol) as the standard grade in September 2021.
Can my car use E10 petrol?
Most petrol cars made from 2011 onwards are fully compatible with E10. You can check your specific vehicle using the official gov.uk E10 compatibility checker. If your car is not compatible, use E5 Super Unleaded instead.
What should I use if my car is not E10 compatible?
Use E5 Super Unleaded, which is available at most UK forecourts. It typically costs 5–10p per litre more than standard E10 but is safe for incompatible vehicles.
Does E10 petrol damage engines?
E10 is safe for compatible vehicles. For incompatible vehicles — particularly older cars, some motorcycles, and small engines — repeated use can degrade rubber seals, hoses, and fuel system components over time.
Does E10 petrol affect fuel economy?
Yes, slightly. E10 can reduce fuel efficiency by around 1–3% compared to E5, because ethanol contains less energy per litre than petrol. For most drivers, this amounts to a small, barely noticeable difference in everyday use.