Is it really worth leaving the motorway in France to save on buying fuel?

Anyone setting off on a French road trip this summer will be familiar with the choice: fill up at the motorway service station, or take a short detour into a nearby town in search of a better price. 

With fuel prices recently increasing again and weighing on household budgets, more drivers are opting for the detour option: but is it worth it?

Public broadcaster France Télévisions put the theory to the test on the A13 motorway towards Normandy, comparing prices on and off the motorway to see which option works out cheaper

The supermarket detour 

Driving a small car (a citadine) with a 42-litre petrol tank running low, the team used a fuel comparison app, which recommended coming off the motorway in Freneuse, a small town in the Yvelines department around four kilometres away: in practice an 11km round trip. 

There, a supermarket forecourt was selling petrol at €2.04 a litre and diesel at €2.20, bringing the cost of a full tank to €85.

The team were far from the only ones making the detour at that station. One motorist filling up there, Gérard Legrand, said he uses the same trick on every motorway trip when running low: he puts €10 of fuel in on the motorway, just enough to get him to a cheaper station further along.

Petrol pricier on the motorway, but not diesel

Returning to the A13, the France Télévisions team found the picture was more mixed than expected. At the motorway service station, petrol was indeed more expensive, at €2.08 a litre, but diesel worked out slightly cheaper, at €2.17. 

For the team's petrol car, leaving the motorway turned out to be the better option - the journalist calculated a saving of around €3 by using the station off the motorway rather than filling up on the A13.

However, The Connexion notes that he did not factor in the 11km road trip driven and therefore the margin will be smaller than the €3 suggested.

Petrol tends to be pricier at motorway services, but that is not always true of diesel, so it is worth checking a comparison app or site rather than assuming either option is automatically cheaper.
And, of course, remember to factor in the mileage it takes to get to the closest petrol station and back to the motorway. 

Leaving the motorway to refuel does not generally affect toll costs: on most closed toll systems, drivers are charged only for the full section of motorway actually driven, so re-entering after a short detour makes little or no difference to the final toll bill. 

What about nationwide data?

Official figures from the government's prix-carburants.gouv.fr website, based on June 2026 data, back up the general trend. 

On average, SP95-E10 petrol at supermarket stations cost between €1.98 and €2.02 a litre, compared with €2.18 to €2.28 a litre at motorway service areas - a gap of around 20 to 25 cents per litre. Over a full tank, that adds up to an average saving of around €11.50 by filling up off the motorway.

Fuel retailers on motorways justify the higher prices by pointing to their running costs, including expensive concession fees, round-the-clock staffing, and a fee they must pay to the motorway operating companies.

The takeaway for drivers

For those planning long journeys through France, the advice is simple: do not assume the motorway is always the more expensive option, particularly for diesel. 

Checking a fuel price comparison app before deciding whether to come off the motorway and weighing any detour against the time and extra mileage involved, remains the best way to make sure a cheaper stop really does save money.

A word of warning when paying for fuel with card

Many French service stations, especially on motorways and overnight, only accept payment via unmanned automated pumps (paiement à l'automate). 

These terminals often place a temporary pre-authorisation hold on the card used (usually €150) which is normally released after the petrol purchase, however some banks will take a few days to credit it back.

For example, you are charged €150 but only buy €35 of petrol so €115 is returned to your account.

This applies to UK-issued cards as much as French ones, so it is worth checking with your bank before a long trip, or paying inside at a manned till where possible to avoid the hold altogether. 

In 2023, The Connexion reported a lot of foreign cards being rejected in unmanned automated pumps.