Fuel Types & Quality Supermarket Fuel

Is supermarket fuel inferior?

Q: Is supermarket fuel inferior?

No. All petrol and diesel sold in the UK must meet the same British Standards (BS EN 228 for petrol, BS EN 590 for diesel) regardless of where it is sold. Supermarket fuel comes from the same refineries as branded fuel. The only difference is that premium branded fuels contain more sophisticated additive packages, which matter mainly for high-performance engines.

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No, supermarket fuel is not inferior in any legally meaningful sense. All petrol and diesel sold in the UK must meet the same British and European standards — BS EN 228 for petrol and BS EN 590 for diesel — whether it comes from Asda or BP.

The Same Legal Standard Applies Everywhere

Regulated by law: UK fuel quality is governed by strict regulations requiring all petrol and diesel to meet defined chemical and performance standards before it can be sold at any forecourt. 2

Same refineries, different pumps: Supermarket fuel and branded fuel frequently originate from the same refineries and are transported through shared pipelines. The base fuel is chemically identical. 2

E10 is standard everywhere: Since September 2021, E10 petrol (containing up to 10% bioethanol) became the UK standard grade. This applies equally to supermarkets and branded stations. 3

Where Branded Fuel Does Differ

Additive packages: Branded fuels such as Shell V-Power or BP Ultimate contain proprietary cleaning and performance additives above the minimum requirement. Supermarket fuel meets minimum additive specs but uses a simpler formulation. 4

Marginal benefit for most drivers: For the vast majority of everyday petrol and diesel cars, the extra additives in premium branded fuel make no noticeable difference to performance or engine life.

Premium grades are different: Both supermarkets and branded stations sell premium grades (e.g. higher-octane E5 petrol). If your vehicle requires or benefits from a premium grade, that consideration applies regardless of where you fill up. 2

The Price Gap Is Real

Supermarkets are consistently cheaper: Supermarket forecourts typically undercut branded stations by 3–8p per litre, using fuel as a footfall driver. On a 55-litre fill, that can mean saving over £4. 1

Prices vary even between supermarkets: Asda, Tesco, Sainsbury's and Morrisons do not always charge the same price, and the gap can shift week to week depending on local competition. 1

Making the Right Choice for Your Car

Check live prices before you fill: Since the base fuel quality is equal, the smartest move is usually to buy the cheapest compliant fuel for your vehicle. CheckFuelPrices shows live prices at 4,000+ UK stations updated every 30 minutes. 1

High-performance vehicles may benefit from branded premium: If you drive a high-performance or turbocharged engine and want to maximise the additive benefit, a branded premium fuel may be worth the extra cost — but this is the exception, not the rule.