Petrol and diesel prices vary by 15p to 20p a litre between forecourts within the same postcode, according to weekly DESNZ road fuel data and the AA's monthly Fuel Price Report. That spread is why fuel-finder apps exist — and why the choice between PetrolPrices, the RAC's Fuel Finder and the AA's Route Planner tools matters. All three claim to show the cheapest pump nearby. In practice they pull from different data sources, refresh at different intervals and cover different chunks of the UK's roughly 8,300 forecourts. Here's how they compare.
Where each app gets its prices
PetrolPrices.com, owned by Reepco, is the largest of the three by user base and claims coverage of around 8,400 UK forecourts. Its data comes from a mix of retailer feeds and crowdsourced updates from its roughly two million registered users. That crowdsourcing is the app's strength and its weakness: prices for busy urban stations tend to be current within hours, while rural forecourts can lag by several days.
The RAC Fuel Finder, embedded in the RAC's Drive site and app, relies primarily on the same industry data pipes used by the Competition and Markets Authority's pump-price transparency scheme, launched in 2023. Since the CMA scheme obliges major retailers to publish prices within 30 minutes of a change, the RAC's feed for supermarket and large-branded sites is close to live. Independents are patchier.
The AA does not run a standalone price-comparison app in the way PetrolPrices does. Instead, its monthly Fuel Price Report provides regional averages and its route planner surfaces forecourt prices along a chosen journey, again drawing on the CMA scheme data. It is best thought of as a planning tool rather than a real-time finder.
How they performed on a real search
We ran the same query — cheapest unleaded within five miles of three postcodes (central Manchester, a market town in Suffolk, and a Highland village) — across all three tools on the same afternoon in autumn 2024. In Manchester, all three surfaced the same Costco and Asda sites at the top, with quoted prices within 1p/L of each other. The differences appeared further down the list.
In the Suffolk test, PetrolPrices flagged a small independent at 4p/L below the RAC's cheapest listed site — but the price was 48 hours old and turned out to be stale on arrival. The RAC's list was shorter but every price checked out at the pump. In the Highland test, coverage collapsed for all three: only two of the six local forecourts appeared on any app, and none showed diesel prices updated within the past week.
The pattern is consistent with what the CMA itself reported in its 2024 road fuel market update: pump-price transparency works well for the major supermarket chains and motorway service areas, but independents — which still account for roughly a third of UK forecourts — remain a blind spot.
Cost, adverts and the small print
PetrolPrices offers a free tier that limits searches and shows adverts, plus a Premium subscription (around £25 a year at the time of writing) that removes both and adds features like price alerts. The RAC Fuel Finder is free and ad-supported but requires an RAC account. The AA's tools are free to browse without an account.
For a driver filling a 55-litre tank once a week, a 3p/L saving is worth roughly £85 a year. PetrolPrices Premium only pays for itself if the app genuinely finds you a cheaper pump than the free RAC tool at least twice a month — and on our testing that margin was not consistent outside dense urban areas.
Which one should you actually use
For urban and suburban drivers, the free RAC Fuel Finder is usually enough: its CMA-linked feed is fast, accurate for supermarket sites, and doesn't require a subscription. PetrolPrices is the better pick if you regularly drive between regions, want price-history graphs, or live in an area with strong crowdsourced coverage — the north-west, London and the M6 corridor score best on that measure.
The AA's monthly report remains the most useful single document for understanding whether pump prices are fair overall, but it is not designed for a Friday-evening detour decision. Treat it as context, not as a finder.
The takeaway
No single app wins across the whole UK. The RAC's tool is the most reliable free option thanks to CMA-mandated data feeds, PetrolPrices is worth paying for only if you drive widely or live somewhere with dense crowdsourced updates, and the AA's report is best for background context rather than live searches. Whichever you choose, the real saving comes from checking before you turn off the motorway — not after you've pulled onto the forecourt.
