How the barometer is calculated
We read the prices displayed by service stations in mainland France on prix-carburants.gouv.fr, the public website of the French Ministry of the Economy. A price counts if it is less than 7 days old at the time of calculation, which runs every 30 minutes.
The ranking
A brand's price is the simple average of its stations' prices. A brand has its own row if it has at least 50 recent prices in France, or 5 in a region. Otherwise, its stations join the "Independents and others" row.
TotalEnergies and Total Access
TotalEnergies and Total Access remain two separate rows: Total Access is the group's low-price network. Both often display the same capped price.
Motorways
Motorway stations are more expensive, and some brands are more present there than others. The "Exclude motorways" filter compares brands at equivalent locations.
How fleet overspend is calculated
The calculator on the Fleets and Sales pages compares two average prices for the selected fuel, in mainland France, motorway stations excluded: the price of the brand used today, and the price of the cheapest brand or the average of the six supermarket brands (E.Leclerc, Intermarché, Auchan, Carrefour, Système U, Netto). Yearly overspend = vehicles × kilometres per year × consumption ÷ 100 × price gap per litre. It does not account for card discounts or fees.
Brands
A station's brand is read from its public label, then from the brand declared in the SIRENE register. Stations without a recognised brand join "Independents and others".
The map and white zones
Each dot is a station, coloured according to the price third it belongs to in the displayed area. A network's white zones are calculated as the crow flies on a 5 km grid.
The tour
The video "The diesel tour of France" follows a single route that passes through every station, calculated on the road network. The route is fixed; the prices are this week's.
Sources
Prices: prix-carburants.gouv.fr (public data, open licence). Region boundaries: IGN, Admin Express (open licence), simplified. Brands: Insee's SIRENE register.
Limitations
Prices are those displayed at the pump: they take into account neither the discounts nor the fees of fuel cards, which are not public. A station that does not publish its price is not counted.
Frequently asked questions
Which brand sells the cheapest diesel in France?
The ranking at the top of the page answers the question, on public prices less than 7 days old. It is recalculated every 30 minutes.
Where do the prices come from?
From prix-carburants.gouv.fr, where every service station is required to declare its prices. Floweet does not collect prices from any other source.
Why exclude motorways?
Motorway stations are more expensive. Excluding them makes it possible to compare brands at equivalent locations.
Can I reuse these figures?
Yes, with the credit "Floweet barometer" and a link to floweet.com.