Booking decision guide
Choose the fuel rule on the actual Spain rental offer, not by the supplier name alone. Full-to-full normally means collecting and returning a full tank. A prepaid or refund rate may take money for fuel at collection, then calculate what comes back after return. Compare the same car, dates and station with every fuel and service charge included. Save the selected rule before driving away and photograph the fuel gauge at both handovers.
Updated
Editor: Ane
Plan the trip
Full-to-full
Check that the car is full at collection and return it full under the booked rule.
Prepaid fuel
Check what is charged at collection, how unused fuel is measured and any service cost.
Refund basis
A gauge increment, receipt or supplier formula can change the amount returned.
Return proof
Keep fuel receipts and dated photos of the gauge and handback.
Two Spain offers for the same vehicle group can have different cash flows at the desk. Use the terms attached to the selected rate, not the general fuel wording on a location page. Keep the pickup and return time identical when comparing rates.
Useful next steps: Choose a Spain pickup first, Separate the card hold from fuel payment
Record whether the offer requires a full tank back, takes an upfront fuel payment, refunds unused fuel or adds a refuelling service charge. A lower rental price does not settle that comparison. Add the security hold separately: money blocked against the car is not the same as fuel bought in advance. If a checkout summary lacks the fuel charge, inspect the rental terms before paying.
A week of driving from Madrid has a different fuel pattern from a short island stay that may use only part of a tank. Under full-to-full, allow time for a reliable final fuel stop near the booked return. Under a prepaid or refund rule, estimate whether the trip will use most of the tank and how the supplier measures the remainder. Do not assume returning with a full tank will cancel a service charge on a different rate.
The labels are shortcuts. The amount charged and refunded follows the exact supplier rate and car, so read its detailed calculation rather than treating every full or refund label as equivalent.
Useful next steps: Compare total rental costs
OK Mobility's full-to-full rule requires a full tank at handover and a full tank at return. If the supplied tank is short, raise it at collection and have the handover record corrected. A short return can add missing litres and a refuelling management cost. Photograph the gauge before leaving and use the fuel type shown on the car and agreement. The same simple return plan may be preferable when a fuel station fits the final drive.
OK Mobility also has a full/refund rate in which the full tank is paid for at collection. It calculates remaining fuel by eighths of the gauge and deducts refuelling management costs from the refund. Centauro's equal-equal option charges for the fuel present at pickup and refunds unused fuel up to the amount initially paid. Those mechanisms can yield different balances after identical driving. Ask for the exact fuel price, gauge record and service charge on the selected offer.
Fuel products vary by company and by rate. The examples below help identify questions for a Spain offer; they are not promises that every branch, vehicle or booking channel offers each option.
Useful next steps: Plan the Fuerteventura Airport return
Goldcar offers full-full and Flex-Fuel options at Fuerteventura Airport. Full-full requires a full return. Flex-Fuel allows a return without topping up and charges for fuel used, but the booked terms can include a service component. Compare the itemised upfront amount, unused-fuel return and any Flex-Fuel cost before choosing it for a short trip. If the offer names another Goldcar fuel system, use that system's own terms rather than assuming it matches this airport example.
Centauro charges for fuel at collection under its full-empty and equal-equal options. Equal-equal refunds unused fuel up to the amount paid at pickup; the full-empty description allows return without topping up, so check that rate's specific refund terms rather than assuming the same calculation. OK Mobility's full/refund uses eighths of the gauge and deducts a management cost. Photographing the gauge is useful evidence, but a photo does not change the contractual increment or service rule.
Fuel disagreements are easier to resolve when the starting level and rate are clear before the car moves. The check takes minutes and belongs with the damage inspection, not at the first petrol station.
Useful next steps: Plan a Madrid Airport handback, Make a collection and return record
Check the gauge against the rental agreement while still at the handover bay. Photograph the gauge with the car and time context, then ask staff to correct a difference. Check whether the vehicle takes petrol, diesel or another energy type before using a pump. Keep the collection receipt for any prepaid fuel and note whether it is a charge or a temporary hold. Do not accept a verbal change to full-to-full without a corrected contract.
The fuel plan needs to fit the booked drop-off, not just the airport name. A garage return, off-site shuttle depot or city branch can need different approach time. Save the return pin and hours before travelling. For a late flight, confirm the supplier's staffed or key-drop process and the point at which it assesses the tank. The airport being open does not establish that a rental return is staffed.
The best fuel rule can fail in practice if the last return is rushed. Choose the return method when you book and test the final drive against the actual branch rather than assuming the nearest forecourt will be convenient.
Useful next steps: Check the Palma Airport return
Choose a suitable station on the final approach, keep its receipt and allow for queues, wrong turns and the rental car park entry. A long drive after refuelling may move the needle enough to trigger a short-fuel assessment. Do not use an unfamiliar fuel type to save a stop. At the bay, photograph the final gauge and mileage before handing over keys and request a receipt or inspection record where available.
Note the gauge increment the supplier uses, the maximum refundable amount and whether a service cost is kept. Do not fill the tank reflexively if the rate has already charged for fuel and refunds only under its own calculation. At handback, record the gauge and keep the final invoice. Check later charges or refunds against the pickup fuel payment and selected terms before disputing a difference.
Fuel policy is one line of the trip cost, not a substitute for checking the rental itself. The cheapest fuel rule on paper may be inconvenient when the first or last travel day is tight.
Useful next steps: Check the card and deposit rules, Return to Spain pickup choices
Hold the driver, station, dates, vehicle group, protection and mileage constant. Then compare rental price, fuel payment, possible refund or refuelling charge, card hold, excess, airport transfer, parking and one-way fee. Treat a refund as conditional until the return gauge and supplier calculation are known. A rate that bundles a fuel service can be sensible for some schedules, but test it against the expected distance rather than a headline promise.
Save a copy of the rate terms and rental agreement, starting gauge, paid-fuel receipt, final refill receipt if applicable, return gauge and handback record. If the invoice differs, use those records to ask the supplier which policy and measurement it applied. Report a fuel error promptly through the booking's support route. A comparison site cannot override the signed fuel terms at the desk.
Use the answers to identify the checks that matter. Check the selected supplier terms and current local rules before booking.
No. It avoids a prepaid fuel calculation when a convenient final stop is available, but compare the full rate, any service cost and your expected driving before choosing.
Not necessarily. Some rates refund a measured remainder, sometimes after a service deduction or subject to a cap. The selected offer controls the calculation.
OK Mobility uses gauge increments of one eighth, with the remaining fuel refund reduced by refuelling management costs. Check that this is the rate in your offer.
The equal-equal option charges for starting fuel and refunds unused fuel up to that amount, so first read the specific contract and compare the planned return level with its refund method.
Keep the selected rate and agreement, pickup and return gauge photos, any fuel receipts, the handback record and the final invoice.