Supermarket vs Branded Fuel: Is There a Real Difference?

The Great Fuel Debate

It is one of the most common debates among UK motorists: Should you pay a premium for branded fuel from BP, Shell, or Texaco, or fill up at the supermarket for significantly less? The answer lies in how fuel is distributed across the country.

It All Comes From the Same Place

All petrol and diesel sold in the UK must meet strict British and European standards (EN 228 for petrol and EN 590 for diesel). Surprisingly, the base fuel sold at an Asda or Morrisons forecourt comes from the exact same regional refineries as the fuel sold at a high-end BP or Shell station.

The Magic is in the Additives

While the base fuel is identical, the difference happens when the tanker truck is loaded. Major brands inject their own proprietary chemical additives into the fuel. These detergents are designed to clean your engine's valves, reduce friction, and prevent carbon buildup over time.

Supermarkets do include additives—they are legally required to—but they typically use standard, off-the-shelf additive packages rather than the advanced, heavily-marketed chemicals used by premium brands.

Which Should You Choose?

For the average commuter driving a standard family hatchback, supermarket fuel is perfectly safe and will save you hundreds of pounds a year. The official CMA data consistently shows supermarkets offering the cheapest prices nationwide.

If you are worried about engine longevity, a popular tactic is to use cheap supermarket fuel for three fill-ups, and then use one tank of branded premium fuel to run detergents through the system. Always check FindPetrol to see just how big the price gap is in your local area today!