What to do if washer fluid, engine oil, or AdBlue is low?

SIXT's standard fuel policy is full-to-full: you pick up the vehicle with a full tank (or a full battery for electric cars) and return it fully fueled or fully charged.

The fuel level at SIXT is measured in eighths — a full tank equals 8/8. The level at which you picked up the vehicle is stated in your rental agreement. We sent this to you by email.

If the tank or battery isn't full at return, SIXT takes care of refueling or recharging. We charge you the actual cost of fuel or electricity plus a service fee. These total costs are usually significantly higher than what you would pay at a gas station. The prices per gallon or kWh are posted at the station and stated in your rental agreement.

Our recommendation: fill up the vehicle before returning it — or conveniently book one of our fuel services in advance. This is especially worthwhile if you'd rather not look for a gas station before returning the car, or don't have time for a fuel stop.

Your SIXT fuel options at a glance:

1. Refuel or recharge yourself before return: Shortly before returning the car, drive to a gas station or charging station and fill up or fully charge the vehicle. Note: If you didn't pick up the vehicle full (e.g., 6/8 tank or 60% battery) and this is noted in your rental agreement, returning it at the same level is sufficient (e.g., 6/8 tank or 60% battery). Tip: Keep your fuel or charging receipt in case of any questions.

2. "Refueling and Charging Service" extra: You pay a one-time service fee, and upon return we only charge you for the amount actually refueled or recharged (gallons or kWh) at the comparable market price. Availability varies by station.

3. "Prepaid Fuel" extra: A full tank or battery charge is already included in the price — you return the vehicle at any level, with no further costs, including for electric vehicles. Please note: unused fuel or electricity is not refunded.

Still need help? Find our contact options below.

In rare cases, the tank might not be completely full at pickup. If that happens, we'll note the actual fuel level in eighths on your rental agreement — and all you need to do is return the vehicle at that same level.

How it works

1. We note the fuel level in eighths on your rental agreement — for example, 7/8. You'll find your rental agreement in your email or in the SIXT App.

2. Return the vehicle with that same fuel level noted on your agreement.

Tip: Snap a photo of the fuel gauge at pickup. That way, you'll have proof on hand if there's ever any question about it.

Level doesn't match? Here's how to sort it out

If your rental agreement shows 8/8 but the tank isn't actually full at pick-up, you've got two easy options:

• At the branch: Just let our team know on-site during business hours — they'll adjust the fuel level for you right away.

• Through our Support Team: Let us know the correct level via Live Chat, and we'll update it so you can return the vehicle at the level it was actually at when you picked it up.

Already returned the vehicle and got charged?

Contact our support team with your rental agreement number, and we'll take a look.

Still need help? You'll find our contact options below.

Always use the fuel type indicated on the sticker on the fuel cap or filler door of your SIXT rental car. This ensures you use the correct fuel regardless of which country you are driving in.

How to identify the correct fuel

• The sticker on the fuel cap or filler door shows the fuel type for your rental car

• Across the EU, standardized fuel symbols are displayed at every pump:

• Circle = Petrol (E5, E10, E85)

• Square = Diesel (B7, B10, XTL)

• Diamond = Gaseous fuels (LPG, CNG, H2)

• If the symbol on the pump matches the one on your fuel cap, it is the correct fuel

Common fuel types by country

Note: In the USA, octane is measured by AKI, not the RON rating used in Europe. US Regular (87) is roughly equivalent to EU 91, and US Premium (91–93) is roughly equivalent to EU 95–98.

Good to know

• Electric vehicles: find charging points via the vehicle's navigation system or a charging app

• Unsure? Contact SIXT Roadside Assistance or use Live Chat rather than refuel on a guess

• Wrong fuel? Do not start the engine — contact SIXT Roadside Assistance immediately

Still need help? Find our contact options below.

You can charge your SIXT electric rental car at any public charging station. Find and pay for charging via common charging apps or directly at the charging point — electricity costs during your rental are your responsibility.

How to find a charging point and charge

1. Find a charging point via the vehicle's navigation system or a charging app

2. Charge and pay — depending on the provider, directly at the point, via app or with the network's charging card

3. Keep your receipts as proof of your charging sessions

Electricity costs

Charging costs during the rental period are the responsibility of the renter

Tip: With the prepaid charging option, you pay for a full charge in advance at a fixed SIXT price and can return the vehicle at any charge level.

Charge level at return

Return the vehicle with the charge level agreed at pick-up (usually full / 100%). If the level is lower, a service fee applies — unless you have booked the prepaid charging option

Help on the road

• Finding charging points: use the vehicle's navigation system or a charging app

• Charging issues: try a different cable or charging point. If the problem persists, contact SIXT Roadside Assistance (number on your rental agreement)

• Empty battery on the road: pull over safely, switch on hazard lights and contact SIXT Roadside Assistance — do not push or tow the vehicle yourself as this can damage the drivetrain

Tip: Use route planning in your vehicle or a charging app to plan charging stops before setting off.

Still need help? Find our contact options below.

You cover the cost of charging during the rental period — both at public charging stations and with SIXT Charge.

Don't want to think about charging before you return the car at all?

With the "Prepaid Fuel" extra, a full charge is already covered — simply return the vehicle at any charge level, with no further charging costs. Just add it at reservation or pick-up.

Charge level at return

Please return the vehicle at the charge level agreed at pick-up (usually full or 80%). If the vehicle isn't sufficiently charged, we'll recharge it and bill you for the cost. Without a pre-booked charging service, this amount includes a service fee and can therefore be significantly higher than public charging prices.

With the pre-booked "Prepaid Fuel" extra, all costs are already covered — no further costs apply.

Still need help? Find our contact options below.

If windshield washer fluid, engine oil or AdBlue is missing, you can top it up yourself. We normally hand over your vehicle with a full windshield washer fluid tank, a full AdBlue tank and sufficient engine oil. If this was exceptionally not the case, we reimburse the proven, reasonable costs of topping up against a receipt. However, if the warning light is red, stop safely, don’t top up anything and call our SIXT roadside assistance. If there is immediate danger, call 911.

What color is the warning light?

• Red: Stop safely, don’t top up anything and call our SIXT roadside assistance: +1 888 7498543 (24/7)

• Yellow or orange: You can drive on to the nearest gas station to top up the missing fluid, provided the display clearly reports the missing fluid and the vehicle runs normally. If you notice a loss of power, noises or further messages, stop safely and call SIXT roadside assistance.

Red warning lights for, for example, oil pressure, coolant or brakes don’t mean that something is missing, but that there is a fault. Stop safely, don’t top up anything and call SIXT roadside assistance: +1 888 7498543 (24/7). Driving on can endanger you and others and damage the vehicle.

How to proceed

1. After stopping safely and with the engine off (never while driving), photograph the warning light in case questions arise later.

2. For engine oil: check the correct oil grade in the owner’s manual. Windshield washer fluid and AdBlue are standardized, so the standard product is enough.

3. Buy the product at the nearest gas station and keep the receipt. In sub-zero temperatures, use washer fluid with antifreeze.

4. Top up as described in the owner’s manual.

5. To get your costs reimbursed, send the receipt as an attachment in Live Chat and give your rental agreement number. Product, date and amount must be visible on the receipt. Please black out your payment details (for example, the card number).

Where AdBlue goes
AdBlue only goes into its own tank, whose filler neck usually has a blue cap. If it gets into the fuel tank, it can damage the injection system.

Next step
Check the color of the warning light: if it is yellow or orange and the vehicle behaves normally, top up; if it is red, stop safely and call our SIXT roadside assistance.

Still need help? Find our contact options below.