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Renting a vehicle is expensive. Getting it back safe without running up the bill with unnecessary expenses is primarily on every car renter’s mind, but unforeseen things happen. It is often as unintentional as putting the wrong gas into a rental car. To avoid using the wrong gas, you must know what type to put into your rental car.

The best way of knowing which gas to put into your rental car is to contact the rental agency before refueling or confirm with the rental agent before leaving their premises what gas to use. Car rental agencies tend to label keys with gas or diesel warnings.

The following are ways to determine what type of gas to put into your rental car and what to do if you put the wrong gas into your rental car.

What Gas To Put In Your Rental Car

The type of gas needed to fill your rental car depends on the model and make. Unfortunately, sometimes things tend to go wrong, and you may find yourself at a gas pump without knowing what gas to use. Following are ten ways to determine what gas to use.

  1. Always have the rental agency's number at hand to dial in case of an emergency. Not knowing what gas to use constitutes an emergency, so call them and gather the relevant information.
  • If you cannot contact the car sharing agency, look in the glove box of the car and locate the car manual containing all the relevant information about the car you rented. You will find the type of gas to use stipulated in the manual.
  • Open the gas flap and look for any labels or warnings that indicate what gas to use. Car rental companies try to avoid gas mishaps as much as possible, and they may have added a label inside the gas flap clearly stating what gas to use.
  • Have a look at the car keys. Car rental companies usually indicate what type of gas to use on the keychain.
  • Google is your friend! Look at the license to confirm the make and model of the car and google to find the relevant information.
  • Have a look at the gas nozzle. If the nozzle fits easily into the gas inlet of the car, you can fill it with confidence. If the nozzle appears too big or fits too snug, refrain from filling the tank, for you may be standing with the diesel nozzle in your hand. You do not want to fill a vehicle that needs gas with diesel and visa-versa.
  • Older model diesel vehicles and trucks sound different from fuel vehicles, and if you are mechanically savvy, you should be able to determine by the engine's sound if you need gas or diesel. Word of caution, modern-day vehicles are not so easily distinguishable, so proceed with caution when using this method.
  • Diesel vehicles have glow plugs. To determine if you are driving a diesel vehicle, turn the key in the ignition without starting it. Several indicators will light up, including the glow plugs, if applicable. Without a glow plug indicator lighting up, you can be sure that ordinary gas will be adequate.
  • Open the fuel cap and smell the fumes since gas and diesel smell differently. Diesel has a robust oil smell; if you are not confident that you will be able to distinguish one from the other, refrain from filling the car.
  1. Unless you specifically asked to rent a diesel model, chances are that you were issued a vehicle that uses gas and can fill up with confidence.

What Gas To Use In Your Rental Car In A Foreign Country

If traveling independently with your vehicle is your style of experiencing a foreign country, you will need to rent a car.

Remember that foreign countries may have different grades of gas and diesel than back home. Therefore, always confirm with the car rental agent what type of gas to use in your rented car and ask them to write it down for later reference, especially if you are not familiar with their language.

What To Do If You Accidently Put Diesel In A Fuel Car?

It is human to err. So, follow these steps if you accidentally filled your rented car with the wrong gas.

  1. Under no circumstances should you start the car upon discovering your error. If you turn on the car, the diesel will run through the engine system and gas parts. In addition, the damage and repair costs will escalate if you start the car.
  • Contact the car rental agency to make them aware of your predicament. The agency may be able to locate or send assistance to transport the car to the nearest workshop to drain the diesel from the tank.
  • If you are fortunate, the vehicle will be fitted with a removable drain on the gas tank that drains the diesel in no time. If you can locate this drain, open it as soon as possible to discard the diesel before help arrives. The mechanic will drain the diesel from the gas tank and then rinse the tank with gasoline before filling the tank with gasoline again.
  • If no removable drain is present, the whole gas tank must be removed, rinsed several times, and re-fitted. Please do not attempt to remove the gas tank yourself.

Do You Need To Fill Up Your Rental Car Before Returning It?

If you have received your rental car with a full tank of gas, ensure that you fill it again before returning it to the rental agency. If you do not fill it, you may be charged a much higher rate by the agency for filling the car than what you would have paid at the gas station.


Things tend to change at short notice. Due to unforeseen circumstances, you may be unable to rent the specific model car you requested. Upon receiving the substitute car, please familiarize yourself with its workings and confirm what gas to use before leaving the rental agencies’ premises.