LPG (liquefied petroleum gas) is a mixture of propane and butane compressed into liquid form and used as a vehicle fuel, commonly called autogas. It burns cleaner than petrol, producing around 15–20% less CO2, and typically costs 60–80p per litre compared to around £1.40–£1.55 for petrol. Most petrol cars can be converted to run on LPG alongside petrol.

Alternative Fuels LPG

What is LPG fuel?

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LPG (liquefied petroleum gas) is a mixture of propane and butane gases that is compressed into liquid form and used as a vehicle fuel. It burns cleaner than petrol, produces fewer harmful emissions, and typically costs significantly less per litre at the pump.

What LPG Actually Is

A byproduct of oil and gas refining: LPG is produced during crude oil refining and natural gas processing. It consists primarily of propane and butane, stored as a liquid under moderate pressure in a sealed tank. 2

Autogas is the vehicle-grade version: When used as a vehicle fuel, LPG is commonly called autogas. It is dispensed from dedicated pumps at filling stations and stored in a pressurised tank fitted to the car. 2

Regulated fuel standard: LPG sold for vehicle use in the UK must meet defined quality standards, just like petrol and diesel, ensuring consistent performance and safety. 2

How LPG Compares to Petrol and Diesel

Lower CO2 and NOx emissions: LPG produces around 15–20% less CO2 than petrol per kilometre driven and significantly lower nitrogen oxide emissions than diesel, making it a cleaner fossil fuel option. 3

Cheaper per litre: LPG typically costs around 60–80p per litre in the UK compared to around £1.40–£1.55 for petrol, though the engine uses slightly more LPG per mile than petrol. 1

Lower energy density than petrol: LPG contains less energy per litre than petrol, so fuel consumption in litres is roughly 20–25% higher, partially offsetting the price saving.

Which Cars Can Use LPG

Converted petrol cars: Most petrol-engined cars can be converted to run on LPG by a specialist, with a secondary tank fitted in the boot. The car can then switch between petrol and LPG.

Bi-fuel operation: LPG-converted vehicles start on petrol and switch automatically to LPG once the engine is warm, giving the flexibility to use petrol when no LPG station is available.

Not compatible with diesel engines: LPG conversions are designed for petrol engines only. Diesel vehicles cannot be converted to run on autogas.

LPG in the Context of the UK's Fuel Transition

A bridge fuel, not a long-term solution: The UK government's Transport Decarbonisation Plan focuses on full electrification of road transport by 2035. LPG is considered a transitional lower-emission fuel rather than a long-term alternative. 3

Shrinking station network: LPG filling stations are less common than petrol and diesel forecourts, so checking availability before travelling is important. CheckFuelPrices can help you locate stations near you. 1

Still viable for high-mileage drivers: For drivers covering high annual mileages in older petrol cars, an LPG conversion can still offer meaningful running cost savings despite the shrinking infrastructure. 4