What Is E10 Petrol?

E10 petrol is a blend of 90% regular unleaded petrol and up to 10% bioethanol — a renewable alcohol made from crops such as sugar beet, wheat, and waste wood. The UK switched from E5 (5% ethanol) to E10 as the standard grade in September 2021, following similar moves across Europe.

The primary purpose of E10 is to reduce CO₂ emissions from road transport. The Department for Transport estimates that E10 cuts transport CO₂ emissions by around 750,000 tonnes per year — equivalent to removing 350,000 cars from the road.

E10 is currently 16.9p per litre cheaper than E5 on average. For most drivers, the small economy loss from E10 is far outweighed by the lower price at the pump.

The vast majority of petrol cars on UK roads are E10 compatible. As a general rule:

• Cars from 2011 onwards — almost certainly compatible
• Cars from 2000–2010 — most are compatible, but check your manufacturer
• Cars before 2000 — less likely to be compatible
• Classic and vintage cars — generally not compatible

If your car isn't E10 compatible, you should use E5 super unleaded instead. You can check your vehicle's compatibility on the government's E10 checker.

Ethanol contains less energy per litre than pure petrol. Because E10 has double the ethanol of E5, you may see a 1–2% reduction in fuel economy. In real-world terms, that's roughly:

• About 3–6 fewer miles per tank on a typical 55-litre fill
• Around £1–2 extra per tank in fuel costs
• Barely noticeable in everyday driving

For most drivers, the price saving of E10 over E5 more than compensates for the marginal economy loss.