UK fuel types explained

E10, E5, diesel, premium diesel, HVO and LPG: what each one is, what it costs compared with the others, and which suits your vehicle.

Most UK forecourts sell two petrols and one or two diesels, and a few also sell renewable diesel or LPG. The "best" fuel isn't the most expensive one. It's the one your vehicle's manufacturer recommends. This guide sets out the facts so you can decide for yourself.

Fuel	Key figure	Renewable content	Price vs standard	Suits
E10 unleaded	95 RON	Up to 10% ethanol	The standard price	Most petrol cars, including all built since 2011
E5 super unleaded	97–99 RON	Up to 5% ethanol	Usually costs more per litre	Cars not approved for E10, and engines whose handbook asks for higher octane
Diesel (B7)	Standard diesel spec (BS EN 590)	Up to 7% biodiesel	The standard price	Almost all diesel cars and vans
Premium diesel	Meets the same spec, plus additives	Varies	Usually costs more per litre	Any diesel. Benefits depend on the vehicle
HVO (renewable diesel)	High cetane (often quoted at 70+)	Up to 100%, or sold as a blend	Usually costs more, and is sold at few forecourts	Diesels the manufacturer has approved for HVO
LPG / autogas	A gas, not a liquid fuel	Fossil (propane/butane)	Usually cheaper per litre, but you get fewer miles per litre	Petrol cars converted to dual fuel

E10 unleaded: the standard petrol

E10 became standard (95 octane) petrol in Great Britain in September 2021 and in Northern Ireland in November 2022. It contains up to 10% renewable ethanol. The government says this cuts CO2 emissions because less fossil fuel is needed.

Compatibility: according to the Department for Transport, around 95% of petrol vehicles can use E10, and all cars built since 2011 can. Some classic and older vehicles, some models from the early 2000s and some mopeds (especially 50cc and under) may not be compatible. Check yours with the GOV.UK E10 vehicle checker.

Pros: widely available, usually the cheapest petrol, and lower CO2. Cons: the government says fuel economy may drop by around 1%, which is unlikely to be noticeable. It's also not suitable for some older vehicles or some garden machinery and boats.

E5 super unleaded (97–99 RON)

Super unleaded contains no more than 5% ethanol and has a higher octane rating, usually 97 to 99 RON. Octane measures how well a fuel resists "knocking", which is uncontrolled early ignition. It is not a measure of energy content. E5 is the grade the government recommends for vehicles that aren't approved for E10, and it remains on sale at filling stations that sell two grades of petrol.

Who might benefit: the RAC says super unleaded is required for some high-performance cars and preferable for others, but that in most cars any benefits are negligible. Using a higher octane than your car needs generally won't harm it. Using a lower octane than the manufacturer specifies could cause problems.

Pros: suits older and non-E10 vehicles, and is the right choice where the handbook asks for it. Cons: usually costs more per litre, and for many everyday cars there may be no discernible benefit.

Standard diesel (B7)

Forecourt diesel in the UK is labelled B7, a blend of up to 7% biodiesel (FAME) with the rest ordinary diesel, which typically meets the BS EN 590 standard. Diesel didn't change when E10 was introduced. Diesel has traditionally suited drivers who do lots of long journeys, but the right choice depends on the vehicle and how you use it.

Pros: sold everywhere and suits almost every diesel vehicle. Cons: it's a fossil fuel, and some modern diesels also need AdBlue (see below).

Premium diesel

Several retailers sell premium diesels with added cleaning and performance additives. They meet the same core standard as regular diesel. The claims vary by retailer, and independent evidence of the benefits for ordinary cars is mixed. The RAC notes that additive packages are designed to help keep fuel injectors clean. It also says that for many cars a premium fuel makes no discernible difference.

Pros: may suit drivers who want added detergents, or whose manufacturer recommends it. Cons: usually costs more per litre, and the benefit depends on the vehicle and how it's driven.

HVO (hydrotreated vegetable oil)

HVO is a renewable diesel, often made from waste fats and oils such as used cooking oil. Pure HVO is made to a different standard (EN 15940). Suppliers describe it as a "drop-in" alternative that can be mixed with ordinary diesel. They also quote a higher cetane number than mineral diesel (often 70 or more, against about 51), which they say can help cold starts. Some forecourts sell blends of HVO and ordinary diesel that meet the standard diesel spec.

Compatibility: check that your vehicle's manufacturer has approved HVO, especially for pure HVO and older engines, because using an unapproved fuel could affect your warranty.

Pros: lower lifecycle greenhouse gas emissions, according to suppliers. Cons: usually costs more, is sold at relatively few forecourts, and not every vehicle is approved for it.

LPG (autogas)

LPG is a mix of propane and butane stored as a liquid under pressure. Cars need a professional conversion that adds a second tank, so they can run on either LPG or petrol. LPG is usually cheaper per litre, but you typically get fewer miles per litre than with petrol. Whether a conversion pays for itself depends on your mileage, the cost of the conversion and whether you can get LPG nearby. Trade press reports that the number of LPG pumps in the UK has fallen in recent years.

Pros: may lower running costs for high-mileage drivers. Cons: upfront conversion cost, less boot space, fewer outlets, and you should tell your insurer.

AdBlue and EV charging

AdBlue is not a fuel. It's a liquid that many modern diesels use to reduce exhaust emissions, and it goes in its own tank. Never put it in the fuel tank.

Electric vehicles charge from the mains or public chargers rather than using liquid fuel, so the pump prices on TankTicker don't apply to them.

Which fuel is right for you?

Use the fuel and grade your vehicle handbook or manufacturer recommends.
Petrol car built since 2011? E10 is suitable. Older car? Use the GOV.UK checker, and if in doubt, use E5.
If you're thinking about premium fuels, HVO or LPG, weigh the extra cost (or the conversion cost) against what your manufacturer says.

Put the wrong fuel in? If you've put petrol in a diesel vehicle, or diesel in a petrol one, don't start the engine or turn on the ignition. The RAC advises telling the forecourt staff, putting the car in neutral, pushing it somewhere safe and calling your breakdown provider to drain the fuel system. Check whether your policy covers misfuelling, as some charge for it. If you've already started the engine, stop as soon as it's safe, switch off and call for help. If a vehicle that isn't approved for E10 gets a single tank of it, the government says it shouldn't be a major problem. Just fill up with E5 next time.

Disclaimer: this page gives general information only, not advice for your vehicle. Always check your vehicle handbook or ask the manufacturer or a qualified mechanic. TankTicker and Tamerton Group aren't responsible for fuelling decisions or their consequences. Product descriptions are based on published information, and we don't endorse or criticise any retailer or brand.