Fuel Policy Compared: Full-to-Full, Prepaid, Same-to-Same and What Each Refund Really Means

A practical comparison of car rental fuel policies: what full-to-full, collect-full and same-to-same mean, why prepaid fuel is never refunded, and how short or excess fuel is billed.

The two basic fuel policies

Fuel policies can differ between providers and national jurisdictions. ECC-Net identifies two main arrangements:

Collect full—return full, commonly called full-to-full: The vehicle is supplied with a full tank. The renter is responsible for using the correct fuel type and refuelling the vehicle before return. If the tank is not full, the renter bears the refuelling cost.
Collect full—return empty: The vehicle is supplied with a full tank, but it does not have to be refuelled before return. Any unused fuel is not refunded, including where the whole tank was paid for upfront.

Prepaid fuel is a paid variation of the collect-full/return-full structure, not a third basic policy. Under a Hertz Fuel Purchase Option, the renter may choose at the start of the rental not to refuel and instead pay for a full tank upfront. Dollar’s prepaid policy likewise says the renter has no obligation to return the vehicle with a full tank.

The wording on the booking and the rental agreement must be checked rather than relying on a display label alone. ECC-Net states that hiring terms should clearly describe the fuel policy and that the total price should include charges such as specific fuel-service charges.

Why prepaid fuel has no refund

The original terms define prepaid fuel as an immediate charge for a full tank, not as a provisional balance waiting to be adjusted after the rental. Hertz’s wording is explicit:

“We charge you at the start of your rental for a full tank of fuel. This price is usually greater than local fuel stations because we include a reasonable service charge element. You will then not need to refill the tank before returning and will have nothing more to pay us for fuel. Please note that we do not provide a refund for unused fuel.”

Its separate Fuel Purchase Option clause likewise says:

“No refunds are given for any unused fuel.”

ECC-Net gives the same consumer-facing rule:

“No refunds will be paid for unused fuel, even if the whole tank was paid for upfront.”

Together, these clauses leave no later adjustment: the full-tank price has already been charged, no further fuel payment is due on return, and the unused portion is expressly excluded from reimbursement.

The calculation method still matters. Sixt’s clause states:

“The surcharge is calculated as 160% on a non-prepaid fuel rate and 10% on a Pre-Paid Amount. For the Pre-Paid Amount Rate to apply you must have purchased this prior to the start of the Rental Period.”

That is a surcharge and purchase-timing rule, not a refund clause. Prepaid fuel should also not be confused with the separate deposit or preauthorisation discussed below.

How a fuel shortfall is calculated

Where a policy uses unit pricing, the supplied terms describe the calculation as the amount of fuel needed to fill the tank multiplied by the applicable rate, with a service charge added if it is not already included.

Under Hertz’s terms:

The refuelling price is a price per litre for filling the tank.
Full details appear on the Rental Agreement collected at pickup.
A Refuelling Service Charge applies on top of the refuelling amount when the company fills the tank, unless that charge is built into the per-litre price.
A calculation of a full tank is provided on the Rental Agreement.
The agreement may show a “maximum refuelling charge.” Hertz also states that its price can be higher than a local petrol station’s price because it covers staff refuelling and the longer turnaround involved.

The practical calculation is therefore not necessarily the local station price. The relevant inputs are the contractual unit price, the quantity required, and any separate service charge.

Sixt uses a different source for the rate. Its terms say the renter is liable for the fuel required to fill the vehicle at a rate that will not exceed the rate calculated under the company’s fuel matrix. The matrix uses average fuel rates and then adds a surcharge. The stated update interval is every 2 weeks.

Dollar and Thrifty’s policy also refers to the rate per gallon specified in the rental agreement. If the company has to estimate the shortfall, it may use either of these methods:

Read the fuel gauge to estimate how much is missing, then multiply that proportion by the manufacturer’s specified tank capacity.
If no fuel was purchased during the rental, use the miles shown by the odometer divided by the vehicle’s estimated average fuel efficiency based on manufacturer specifications.

The policy notes that these estimation methods necessarily involve human judgement. This is another reason to use the applicable policy’s receipt and location conditions rather than assuming that the renter’s own estimate will determine the charge.

Distance and receipt conditions

The cited Dollar and Thrifty policy says the renter must refuel within a 10-mile radius of the rental return facility and present a fuel receipt to avoid a refuelling charge, unless the prepaid option was chosen.

The distance is measured from the refuelling location to the rental return facility. If the refuelling takes place outside that radius, or the receipt is not presented, the stated conditions for avoiding the charge have not both been met. A refuelling charge may therefore apply.

Hertz has a separate receipt instruction: when returning the vehicle full, the fuel receipt should be placed on the driver’s seat. Neither requirement should be treated as a universal rule. The applicable provider policy and rental agreement control.

Extra fuel does not create a refund

The official wording supplied does not provide a refund entitlement for fuel added beyond the required level.

For prepaid fuel, the position is direct: Hertz says no refunds are given for unused fuel, and ECC-Net says there are no refunds for unused fuel even when the whole tank was paid for upfront.

For the self-refuelled full-to-full route, Hertz says that refuelling the vehicle yourself means there will be no further fuel charges on return. That is not a promise to purchase or reimburse extra fuel. It describes the absence of another charge when the contractual full-tank condition is met.

FTC consumer guidance also notes that most companies require the vehicle to be returned with a full tank and that prepaid fuel may cost more than filling up personally. It does not create a refund for surplus fuel. Extra fuel should not therefore be treated as a credit under these terms.

What same-to-same means for a fuel car

Same-to-same is not a third universal policy alongside full-to-full and collect-full/return-empty. The evidence contains no single official definition of same-to-same for petrol cars across all providers.

Where that wording is used, its practical meaning is a recorded-level comparison:

The fuel level at pickup is the reference.
That level or amount should be recorded in the rental documentation.
The vehicle should be returned to the recorded level.
Returning below that reference can lead to a refuelling or recharging charge under the applicable policy.

Hertz’s deposit provisions include a fuel amount unless the Fuel Purchase Option was bought. The fuel cost varies according to the vehicle’s make and model, is determined at collection, and is recorded on the Rental Agreement. This supports checking both the pickup fuel entry and the deposit calculation.

The direct “same level” language in the supplied terms is from the electric-vehicle section: returning with at least the recorded level, or 80%, whichever is lower, avoids further recharging costs; returning below the level recorded at pickup triggers recharging fees. That clause is a useful comparison, but it is not evidence of a universal petrol-car definition.

Specific fuel wording remains important. Sixt’s petrol-car clause says the vehicle is delivered with a full tank and must be full at the end unless the prepaid option applies. If a booking screen uses same-to-same but the rental agreement specifies full-to-full, the full-tank condition is the more precise stated requirement.

Fuel-return checklist

To follow the disclosed fuel condition and reduce the risk of an avoidable deduction:

Read the fuel policy before accepting the booking. Identify whether the agreement requires a full tank, permits an empty return, or applies a prepaid option. Check the unit rate, any service charge and the treatment of receipts. CCPC’s practical guidance is to check the fuel policy in the rental agreement to avoid extra charges when returning without a full tank.
Check the vehicle at collection. Note the fuel gauge or level and make sure the fuel entry and relevant amount appear on the Rental Agreement. Also confirm the correct fuel type.
Apply the selected policy exactly. Under full-to-full, refuel before return. Under prepaid fuel, follow the no-obligation-to-refuel wording but do not expect unused fuel to be refunded.
Keep the refuelling receipt. Follow the provider’s presentation instructions. Hertz asks for the receipt on the driver’s seat when returning full; Dollar and Thrifty require presentation of the receipt and refuelling within the stated 10-mile radius.
Do not rely on proximity alone. A receipt outside the applicable radius may not meet the cited policy, just as a receipt from a nearby station may not satisfy a different provider’s requirements.
Check the fuel level before handing over the vehicle. Compare it with the full-tank or recorded-level requirement in the agreement. Fuel supplied by the company may attract both the fuel charge and a service charge, depending on how those charges are structured.
Separate deposit timing from fuel refunds. Hertz says the reserved credit amount is released or repaid after the vehicle is returned and rental charges have been paid, but it may take up to 30 days for an unused preauthorisation or deposit to be released. That release is not a refund of unused prepaid fuel.

Frequently Asked Questions

Why can two fuel charges for similar quantities differ? One charge may use the amount missing multiplied by a contractual per-litre or per-gallon rate, while another uses a provider’s fuel matrix. A separate service charge may also be added or built into the unit price.

Is a petrol receipt a reimbursement? No. Under the cited Dollar and Thrifty policy, the receipt is evidence used to avoid a refuelling charge, subject to the 10-mile radius condition. Hertz asks for the receipt to be left on the driver’s seat when returning the vehicle full.

Does same-to-same always replace full-to-full? No. Same-to-same uses the recorded pickup level as its practical reference, but a specific full-tank clause still controls where the agreement contains one. The cited Sixt petrol-car terms require a full tank at return unless prepaid fuel applies.

Can I refuel well away from the return facility? Not under the cited Dollar and Thrifty condition for avoiding a charge. Refuelling must be within a 10-mile radius of the rental return facility, and the receipt must be presented.

Does a returned deposit mean unused prepaid fuel was refunded? No. Deposit release and prepaid-fuel refunds are separate contract matters. Hertz says an unused deposit or preauthorisation may take up to 30 days to be released, while its prepaid-fuel terms expressly deny a refund for unused fuel.