E10 vs E5 Petrol: What You Need to Know

Ethanol is an alcohol made from crops (wheat, sugar beet). It's blended into petrol to reduce carbon emissions — the UK government mandated the switch to E10 as part of its net-zero strategy. Bioethanol produces fewer CO2 emissions when burned than pure petrol.

The downside: ethanol contains less energy per litre than petrol, so your car uses slightly more fuel to travel the same distance. In practice, most drivers see a 1–2% reduction in fuel economy on E10 compared to E5.

95% of petrol cars on UK roads are compatible with E10. If your car was manufactured after 2011, it almost certainly is. Some cars made between 2000–2011 are also compatible.

Cars that may not be compatible include:

• Classic and vintage cars (pre-2000)
• Some early 2000s models from certain manufacturers
• Mopeds and small motorcycles with older engines

If you accidentally put E10 in an incompatible car once, it won't cause immediate damage. But prolonged use can degrade rubber seals, gaskets, and fuel lines. If in doubt, stick to E5 super unleaded and check your vehicle handbook.

E10 is typically 8–12p per litre cheaper than E5 super unleaded. On a 50-litre tank, that's £4–6 savings per fill-up, or roughly £200–300 per year for a typical driver.

The 1–2% efficiency penalty means you'll use slightly more E10, but the price difference far outweighs this. Even accounting for reduced MPG, E10 saves you money overall.

Check current E10 and E5 prices by brand →

Use E10 if:

• Your car was made after 2011 (almost all are compatible)
• You want to save money at the pump
• You don't have a specific requirement for higher octane

Use E5 if:

• Your car is not E10 compatible (classic or pre-2011 model)
• Your manufacturer recommends 97+ octane fuel
• You have a high-performance engine that benefits from higher octane