Is E10 safe for every car?
No. Most modern petrol cars can use E10, but some older, classic or specialist vehicles need E5. Check the vehicle manual, fuel flap label or official E10 checker.
E5 vs E10 petrol
E5 vs E10 petrol: price, ethanol and RON explained
Compare E10 petrol, super unleaded E5 and RON 97+ and RON 99 labels before choosing the fuel that fits your car and route.
E10 vs E5
E10 is the standard. E5 is the super grade.
In the UK, standard petrol is E10 and is normally 95 RON. Super unleaded is normally E5 and RON 97+ or higher. The important difference is not only price: older or specialist vehicles may need E5, and some performance or tuned cars may need a higher RON fuel.
Route & Fuel helps compare E10 and E5 as separate fuel choices, then the app checks price, detour, fuel range and how far each stop is from your journey before you choose a stop.
Driver guidance
Check the car first, then compare the price.
For fuel choice, your owner’s manual and fuel flap label matter more than a one-size-fits-all website recommendation. If your car asks for a minimum RON, use that or higher.
| Fuel / label | What it usually means in the UK | Who should care |
|---|---|---|
| E10 petrol | Standard 95 RON petrol with up to 10% renewable ethanol. | Most modern petrol cars, unless the vehicle is not E10 compatible. |
| Super unleaded E5 | Higher octane petrol, generally RON 97+ or higher, with up to 5% ethanol. | Older E10-incompatible cars, some performance cars, tuned cars and drivers whose owner's manual asks for higher octane. |
| RON 97+ / RON 99 | RON is the octane rating. Higher RON resists knock better in engines designed or tuned to use it. | Cars that require or recommend high-octane fuel; benefits in ordinary engines are usually limited. |
E5 and E10 FAQs
Questions drivers ask
Will E5 make every car faster?
Not necessarily. Higher octane fuel matters most when the engine is designed, tuned or mapped to use it.
Can I mix E5 and E10?
For E10-compatible vehicles, mixing E5 and E10 in the same tank is generally fine. Keep following the car manufacturer’s fuel guidance.