Here's a number that surprises most drivers the first time they see it: an RAC investigation for ITV's Tonight programme found a 27p per litre difference between two filling stations a short drive apart. Not on opposite sides of the country - a short drive apart. On a 50-litre tank, that single gap is worth over £13.
Most drivers fill up wherever happens to be convenient at the time. For someone doing an average weekly commute, the difference that habit costs is real but modest. For a driving instructor covering several hundred miles a week, lesson after lesson, pickup after pickup, that same habit compounds into something genuinely worth paying attention to.
The gap is bigger and more constant than people assume
This isn't a one-off finding from an unusually dramatic investigation. Routine day-to-day analysis of UK fuel pricing data shows spreads of 10 to 20p per litre are common within the same town, and motorway service stations typically charge 10 to 20p more per litre than nearby town forecourts because of their captive audience. Supermarket forecourts - Tesco, Asda, Sainsbury's, Morrisons - consistently undercut the wider average, often by several pence per litre, partly because fuel is used as a loss-leader to bring shoppers onto the site.
None of this requires driving further out of your way than makes sense - a saving of a few pence a litre isn't worth a 20-minute detour. But a garage you already pass on your normal route being consistently a few pence cheaper than the one next to it is a saving that costs you nothing extra to take.
Why it matters more for instructors specifically
Most drivers fill up once a week, maybe twice. An instructor doing several hundred business miles a week, across pickups, lessons, test centre runs and driving between pupils, is filling up far more often - which means the per-litre gap gets multiplied by a much larger number of litres, month after month.
Take an instructor covering 500 miles a week at roughly 40mpg. That's around 57 litres a week, or close to 3,000 litres a year. Consistently paying even 5p a litre less than the local average - well within the normal day-to-day spread - works out to roughly £150 a year. At 8p, it's closer to £240. That's not a dramatic single saving. It's a quiet, compounding one that costs nothing but a moment's comparison.
Building the habit without adding admin
The reason most drivers don't act on this isn't scepticism about the savings - it's that comparing prices feels like one more thing to check on top of an already full working day. The habit only sticks if it's genuinely low-effort: glance at current prices near your usual route before you fill up, rather than researching from scratch every time.
- Check before you're running low - comparing prices with a full tank of runway removes the pressure to just fill up wherever's nearest
- Know your regular route's cheapest option - most instructors have a handful of garages they naturally pass; knowing which is consistently cheapest turns comparison into habit
- Avoid motorway services unless genuinely necessary - the premium there is rarely worth it for a short top-up
- Don't chase small gaps with a big detour - a 3p saving isn't worth ten minutes out of your lesson schedule
See current prices at garages near you, pulled from official UK fuel pricing data, without switching to a separate app. It sits alongside your daily check and HMRC mileage tracking, so comparing prices before a fill-up becomes part of the same routine you're already running.
Frequently asked questions
This article references RAC Fuel Watch reporting, UK Government Fuel Finder open data, and industry analysis of forecourt pricing patterns, current at the time of writing. Fuel prices vary continuously and by location - always check current prices before making purchasing decisions. This is general information, not financial advice.