Supermarket vs branded: the real price gap in 2026
The oldest question on the forecourt: is the cheaper supermarket fuel as good as the branded stuff, and is branded ever worth paying more for? The honest answer is that for most drivers, most of the time, the supermarket wins - but there are real exceptions.
The price gap is real
Supermarket forecourts consistently average a few pence a litre below branded sites. Over a 55-litre fill that is a pound or two each time, and several tanks a month adds up to real money over a year. The gap is widest where supermarkets compete hard with each other.
Is the fuel actually different?
Standard petrol and diesel sold in the UK must meet the same British and European fuel standards wherever you buy it, so the base product is comparable. The genuine difference is in additive packages: premium and some branded fuels carry higher doses of detergents and friction modifiers designed to keep injectors and valves clean over time.
When premium pays off
For a modern car driven normally on standard fuel, you are unlikely to notice a difference. Premium grades can make sense for high-performance engines that specify them, for older engines with known deposit problems, or as an occasional "clean-out" tank. As a permanent upgrade for an ordinary car, the maths rarely works.
Let loyalty decide the tie
Where two sites are close on headline price, loyalty schemes break the tie. Clubcard, Nectar at Esso and Sainsbury's, BPme and the rest can shift the real cost by a few pence. Fuel Checker re-ranks forecourts by what you actually pay after rewards, so you are comparing like with like rather than the number on the totem.
