EfficientRefuel
ES
Legal notice and privacy
Last updated: 13 September 2026
1. Who runs this website
EfficientRefuel is a free, personal project available at efficientrefuel.com. It is not run for profit, shows no advertising, sells nothing, and there is no company behind it.
For anything to do with this website — privacy questions, price errors or anything else — you can write to:
- Contact: hola@efficientrefuel.com
2. What this service does
EfficientRefuel works out which filling stations along your route are worth stopping at so you spend as little as possible, taking into account your vehicle’s consumption, how much fuel you want to arrive with and each station’s opening hours.
It is free to use and requires no sign-up or account.
3. About the prices: the important part
EfficientRefuel does not set or control fuel prices. It takes them from third-party sources and shows them exactly as received. The price charged at the pump always prevails over the one shown here.
Where the prices come from:
- Spain: official open data from the Spanish Ministry for the Ecological Transition.
- France: French government open data (Prix des carburants).
- Andorra, Portugal and Germany: HERE Fuel Prices, a commercial data provider.
Stations report their prices throughout the day, so a price may have changed since the last update. A source may also contain errors, gaps or omissions that EfficientRefuel cannot detect.
Results are therefore indicative and do not constitute an offer or a guarantee of price. To the extent permitted by law, we accept no liability for losses arising from decisions based on this information, for errors in third-party data, or for interruptions to the service.
The same applies to consumption, range and opening-hours calculations: they are estimates. Real consumption depends on your driving, load, traffic and weather, and published opening hours may not match reality.
4. Privacy
No accounts, no profiles
EfficientRefuel does not ask for your name, email, phone number or any other identifying detail, and builds no account or profile of anyone. All calculation happens inside your browser. What you type in — origin, destination, vehicle, settings — is not sent to any server of ours while you use the app. The origin, destination and departure time are forgotten once you close the page; your car details and preferences are saved on your own device, but only if you agree: after the first calculation the site asks whether you want it to remember them, and unless you say yes nothing is saved. You can change your mind at any time (how to do so is explained below).
The one exception, explained in full below: if you press “Open in Google Maps” or “Open in Waze”, an anonymous record is stored with the departure and arrival areas rounded to about 25 km, without your IP and without anything that could identify you. See “Trip statistics”.
Your location
The “use my current location” button only works if you press it and your browser explicitly asks your permission. Your coordinates are used to set the starting point and are sent to the address service to turn them into a place name. They are not stored. You can skip that feature and type the origin yourself.
Third-party services
To work, your browser connects directly to these services. Each receives your IP address and the specific data it needs in order to answer, and handles that information under its own terms:
| Service | What for | What it receives |
|---|---|---|
| Spanish Ministry · via Cloudflare Workers | Official prices | Nothing about your route: the full national list is downloaded |
| French government | Official prices | Nothing about your route |
| HERE Fuel Prices | Prices in Andorra, Portugal and Germany | The shape of your route |
| Project OSRM | Working out the road route | Origin and destination coordinates |
| Esri ArcGIS and Open-Meteo | Address search | What you type in the fields and, if you use it, your location |
| OpenStreetMap | Map imagery | The map area you are looking at |
| Fleet Catalog | Vehicle catalogue (optional) | The make and model you look up |
| unpkg | Map libraries | Only the file request itself |
| Cloudflare Web Analytics | Counting visits | Page visited and technical browser details, no cookies |
| Cloudflare Workers · ours | Official prices and trip statistics | The anonymous record described above, when you press a navigation button |
If you press “Open in Google Maps” or “Open in Waze”, you leave this website for those services, which apply their own policies.
Trip statistics
When you press “Open in Google Maps” or “Open in Waze”, and only then, an anonymous record is stored so we can learn which journeys people plan and which stations end up being recommended on them. We use it to improve the app and to understand the market.
What that record contains:
- The date (the day, without the time).
- The departure and arrival areas, rounded to cells of about 25 km. The whole of Madrid is three or four cells: enough to know the corridor, not where you set off from.
- The rounded distance, the fuel, the consumption as a band (not the exact figure) and which navigation app you opened.
- The official identifier of the recommended stations, and only when they come from public sources (the Spanish Ministry, the French government). That is business data, not personal data.
What is not stored: your IP address, your name, the exact origin and destination addresses, the time, or any identifier that could recognise you or link two of your trips. Each record carries a single-use random number whose only purpose is to group the stops of that one trip.
Your IP is used transiently to prevent abuse (someone skewing the statistics by sending data in bulk), turned into an irreversible code with a key that changes daily, and is never stored. The data is held by Cloudflare within the European Union.
Visitor measurement
We use Cloudflare Web Analytics to see how many people visit and which pages they view. It is an aggregated, cookie-free measurement: it creates no identifier that could follow you between visits or across websites, it profiles nobody and it sells no data to third parties. It records technical details of each visit (page, referring link, browser type and approximate country) that cannot identify you.
Cookies and storage
This website uses no cookies — no session, analytics or advertising cookies — and there is no banner to accept.
It is worth being precise, because this is often explained badly. The applicable rule (Article 22.2 of the Spanish LSSI, which transposes Article 5(3) of the ePrivacy Directive) is not only about cookies: it is about storing or reading any information on your device, and that includes the local storage this site uses. The absence of cookies is not, on its own, the reason you are not asked for permission.
The reason is a different one, and it is the simplest of all: we ask you. Your car details are saved only if you answer yes to the question shown after your first calculation. If you do not answer, or answer no, nothing is saved. And at the foot of the form there is always a line telling you which situation you are in, with a button to change it in either direction.
The other two items on the list — the temporary price copy and the iPhone notice flag — do rely on the rule’s exemption: they are strictly necessary to provide the service you requested. The first avoids downloading several megabytes on every calculation and overloading a public server; the second avoids showing you again a notice you have already dismissed. Neither identifies anybody, neither can be used to track you, and neither leaves your equipment.
Three things are kept on your device, and none of them ever leaves it:
- Your car details and preferences: fuel type, range, consumption, occupancy, discount cards and advanced settings. They are saved only if you accept the question shown after your first calculation, so you do not have to fill in more than twenty fields on every trip. They include neither your routes, nor your origin, nor your destination, they are not sent to any server and they identify nobody: they are the same numbers you typed yourself. Whenever something is saved, the site says so at the foot of the form and offers a “Forget them” button that deletes it instantly.
- A temporary copy of the public price list (about 30 minutes, so the site loads faster and the public server it comes from is not overloaded).
- If you dismiss the install notice on iPhone, a flag so it is not shown again.
All three disappear when you clear your browsing data. In a private window, none of them is saved.
Your rights
The records we keep are anonymous by design: they carry no name, no IP and no identifier that could tie them to you or to each other. That means we cannot locate “your” data either to show it to you or to delete it, simply because nothing points to you. This is not an excuse to brush you off: it is the consequence of deliberately building it that way.
If you would rather not have even that anonymous record stored, just don’t press the navigation buttons: note the station down and look it up in your maps app yourself. The result of the calculation is exactly the same.
For any privacy question, write to the contact in section 1. For data received by the third-party services, you would need to contact each of them directly.
5. Use of the service
You may use EfficientRefuel freely to plan your trips. Automated data extraction, overloading the service, and any use that harms its operation or that of the data sources it depends on, are not permitted.
The service is provided “as is”, with no guarantee of availability. It may be interrupted or changed at any time.
6. Intellectual property
The EfficientRefuel name, logo and website design belong to its operator. Price data belongs to its respective sources and is shown under their terms. Mapping comes from OpenStreetMap and its contributors, available under the ODbL licence.
7. Governing law
This notice is governed by Spanish law. For any dispute, and unless consumer legislation provides otherwise, the courts of the operator’s domicile shall have jurisdiction.