UK Petrol & Fuel Types Guide ⛽
Confused by E10, E5, B7? Compare average prices for every fuel type sold in the UK and find out which one is right for your car.
Standard 95 octane petrol containing up to 10% renewable ethanol. The default fuel for most petrol cars.
Higher octane (97-99) petrol with up to 5% ethanol. Provides better performance for some engines.
Standard diesel containing up to 7% biodiesel. Suitable for almost all diesel engines.
High-performance diesel with extra cleaning additives for better engine health and efficiency.
Understanding Fuel Labels
E10Standard Petrol
The standard grade of petrol in Great Britain. It contains up to 10% renewable ethanol. Compatible with almost all petrol cars built after 2011.
E5Premium Petrol
Contains up to 5% renewable ethanol. Usually sold as 'Super Unleaded' (97+ octane). Required for some older classic cars and high-performance vehicles.
B7Standard Diesel
Calculations based on standard diesel containing up to 7% biodiesel. Used in almost all diesel cars and vans.
Frequently Asked Questions
What is E10 petrol?
E10 is standard unleaded petrol containing up to 10% renewable ethanol. It was introduced to cut CO2 emissions. It is compatible with almost all cars built after 2011.
What is B7 diesel?
B7 is the standard diesel grade, containing up to 7% biodiesel. It is safe for all diesel engines and is what you get from the standard black nozzle.
What is Super Unleaded (E5)?
E5 contains only up to 5% ethanol and has a higher octane rating (97+ ron). It costs more but is required for some classic cars and high-performance engines.
Is Premium Diesel worth it?
Premium diesel (e.g., V-Power, Ultimate) has extra detergents to clean the engine. It offers marginal MPG gains but is significantly more expensive.
Can I use E10 in my classic car?
Older cars (pre-2002) may have seals that differ with ethanol. Use the government checker. If in doubt, use Super Unleaded (E5) which is safe for classics.
Why is E5 more expensive?
It is lower volume, harder to make/store, and contains less cheap ethanol. Retailers charge a premium for it as a luxury/enthusiast product.
Will E10 reduce my MPG?
Slightly. Ethanol has less energy than pure petrol. You might see a 1-2% drop in MPG, but usually the cheaper price of E10 offsets this efficiency loss.
Can I mix E10 and E5?
Yes. They mix fine in the tank. If you are stuck, filling half and half is no problem for the engine.
What is 'City Diesel'?
An older term for low-sulphur diesel. All diesel sold at pumps today meets ultra-low sulphur standards, so the term is largely obsolete.
Do supermarkets sell Super Unleaded?
Most do (e.g. Tesco Momentum 99). It is often much cheaper than branded Super Unleaded (like Shell V-Power) while offering similar high octane.
Is LPG still available?
LPG availability is shrinking rapidly as Shell and BP remove pumps. Use our map to find the few remaining specialists if you run an LPG car.
What if I put petrol in a diesel car?
Don't start the engine! Call a misfuel service immediately. Circulating petrol through a diesel fuel pump destroys it instantly.
What is the octane of regular petrol?
In the UK, standard E10 is 95 octane (RON). This is higher than the 'Regular' 87 in the USA.
Why is red diesel cheaper?
Red diesel is taxed lower for agriculture/construction. It is illegal to use in road cars (`red` dye stains the tank). Heavy fines apply.
Does fuel go off?
Yes. E10 naturally degrades over 6-12 months. If storing a car, leave the tank empty or use a stabilizer additive.
Is AdBlue a fuel?
No, it's an exhaust fluid for modern diesels to reduce NOx. You do not put it in the fuel tank! It goes in a separate blue filler cap.
What is HVO diesel?
Hydrotreated Vegetable Oil. A 100% renewable diesel replacement. It works in standard engines but is currently rare and expensive to find at pumps.
Why does E5 nozzle look green?
Green is for Unleaded. The grade is written on the label (E10 or E5). Always read the label circle before lifting the nozzle.
Is high-octane fuel cleaner?
It burns slightly cleaner in optimized engines, but for a standard hatchback, the emissions difference is negligible compared to driving style.
Will prices of E10 rise?
They follow oil prices. The ethanol content actually links it slightly to crop prices (corn/wheat), but crude oil is still the main driver.