Supermarket Petrol

The supermarkets source fuel from the same refineries and terminals as branded suppliers. Tesco and Sainsbury's fuel is often sourced from the same production facilities as Shell or BP. The difference is in the additive package — branded fuels include proprietary detergent and friction-modifier packages (Shell's PurePlus technology, BP's ACTIVE technology), while supermarket fuel meets the BS EN 228 standard minimum. Whether these additives make a meaningful real-world difference is debated — most modern engines with direct injection can benefit, but older port-injected engines less so.

The CMA's 2023 investigation found that supermarkets maintained higher-than-warranted margins relative to wholesale costs during the 2021–2022 price spike, contributing to the CMA transparency mandate. Since then, supermarket prices have tracked wholesale costs more closely.

For WorthThePump users, supermarket stations frequently appear as 'Worth It' results because their prices are consistently lower. The question becomes whether the nearest supermarket forecourt is genuinely accessible given your route — a Tesco Extra 4 miles off the motorway may not beat a BP at the next junction when detour costs are factored in.

Loyalty discounts: Tesco Clubcard and Nectar (Sainsbury's) can add further savings — 1–2p/L off for qualifying purchases — which aren't reflected in the live price data. Worth factoring in manually if you're a loyalty card holder.