Supermarket price competition remains the primary catalyst for lower fuel prices across Britain. However, recent data highlights growing variance in pump prices even within the same supermarket chains across different towns.

Why Do Prices Differ Between Stores in the Same Chain?

Unlike grocery pricing in supermarket aisles, which is generally uniform nationwide, UK fuel pricing operates on localized competitive clusters. Supermarket pricing algorithms assess:

• Proximity to Competitors: A supermarket forecourt located within 3 miles of another competitor will typically price 2p to 5p cheaper than an isolated branch.
• Logistical Terminal Distance: Proximity to major coastal oil import terminals (such as Stanlow, Fawley, or Grangemouth) reduces distribution trucking costs.
• Local Demand Volume: High-turnover forecourts can operate on narrower profit margins per litre.

The Diesel vs Unleaded Margin Gap

Historically, diesel commanded a modest premium over unleaded due to European refining constraints. While the premium widened significantly in recent years, increased availability of alternative refinery imports has brought standard diesel prices closer to unleaded averages in many UK counties.

Finding the Best Supermarket Deals

To ensure you never pay more than necessary, always check live search results before filling up. Supermarket loyalty apps (such as Tesco Clubcard, Asda Rewards, and Morrisons More) occasionally offer bonus vouchers or fuel discounts that further enhance savings.