Full-to-full and the other fuel policies, decoded before they cost you

Full-to-full means you collect the car with a full tank, return it with a full tank, and pay only for the fuel you actually burned, at the station price you chose. It's the only fuel policy with no built-in margin for the agency, which is exactly why the alternatives exist. Here's what each policy really costs, the refuelling routine that keeps full-to-full clean, and the one French fuel mistake that no policy forgives.

The policies, ranked

• Full-to-full. The fair one. Your only obligation is returning the tank as full as you got it. Cost above your own driving: zero, if you follow the routine below.
• Full-to-empty, or prepaid fuel. You buy the tank upfront at the agency's rate and return the car as empty as you dare. Sounds convenient, prices badly: the agency's per-litre rate typically beats the autoroute's worst station, and nobody returns a tank truly empty, so the unused half is a donation. Rational only for the rare trip that genuinely finishes on fumes at the return gate.
• Same-to-same. Return with the same partial level you received. Fair in spirit, messy in practice, since "five-eighths of a tank" is an argument waiting for a gauge photo. Photograph the gauge at pickup and return if you're handed this one.
• Prepaid with refund. The refund covers unused fuel at a rate below what you paid, minus sometimes a service fee. Read: full-to-empty with better marketing.

If a booking doesn't state the policy, that's not a detail to leave for the counter, it's the second most expensive line in the contract after the excess, and it belongs on the same pre-booking checklist as the rest of the charges that inflate cheap rentals.

The full-to-full routine

Three habits make the fair policy watertight:

1. At pickup, check the gauge before leaving the lot. Not quite full? Back to the desk, noted in writing, two minutes. Driving off on seven-eighths makes the missing eighth yours at return.
2. Fill up within a few kilometres of the return point, and keep the receipt. Most contracts expect the final fill within 10 to 20 kilometres of drop-off; the receipt with its timestamp and location is what closes any "the tank wasn't full" conversation before it opens.
3. Refuel at supermarkets, not the autoroute. French supermarket stations (Leclerc, Carrefour, Intermarché) sell the same fuel €0.20 to €0.30 per litre below motorway services. With SP95-E10 averaging around €2 per litre nationally, current averages tracked at Carbu.com, a 45-litre tank filled smart saves a lunch.

The mistake no policy covers: wrong fuel

France runs two pump worlds, Sans Plomb (SP95-E10, SP98) for petrol and Gazole for diesel, plus E85 pumps that look temptingly cheap and belong only in converted cars. Misfuelling is excluded from every standard cover and most waivers: the drain, tow and repair land on you in full, potentially over €1,000. Before your first fill, check the fuel flap or key tag, and treat the green E85 handle at €0.80 a litre as decoration. If the wrong nozzle has already been in, don't start the engine; call the agency's assistance line and let them decide the recovery.

Rental EVs replace this whole subject with charging etiquette, a different game covered in our EV charging in France guide.

Every rental we run in Paris is full-to-full with the policy stated on the booking page, which you can see on our Paris rental rates; the routine above is all it takes to return one without a fuel line on the invoice.