What happens if you pump gas with your car on?

What happens exactly if you pump your gas with your car on? Normally nothing much, but in the worst-case scenario, you may start a fire, or even cause an explosion. So, why take your chances?

When gas vapors mix with heat and electricity, flames could erupt and cause a potential fire. This rarely happens, but it poses a real threat. It is neither a myth nor an urban legend. Pumping gas with your car on can create conditions to start a fire.

Always observe the signs on fuel pumps that instruct you to turn off your car while pumping. Failure to do so is a potential safety hazard and it is illegal according to US law.

Table of Contents

Can you pump gas with the car on?

Technically, yes, you can pump gas with the car on, but you shouldn’t. From a strictly mechanical point of view, under normal circumstances, pumping gas with your car on won’t cause any damage to your car. However, all it takes is a single spark to ignite the gasoline.

So no, you shouldn’t pump your gas with the car on, even if you can. You may cause a far greater issue than just damage to your car if you decide not to follow simple instructions on the placards on the fuel pumps.

Three basic elements are needed in order for a fire to take place and those are gasoline, an oxidizer, and some source of heat or ignition. These are some common sources of ignition:

  1. Static electricity – there is always a chance, however small, of gas vapors igniting if they come in contact with static electricity. To prevent this from happening, remember to always touch something made of metal, such as your car’s door before operating a gas pump.
  2. Faulty spark plugs – normally, they ignite a petrol and air mixture that makes a car run. If the insulation around the plugs breaks down, the electricity can potentially ignite the car. Although this is unlikely to happen, we advise that you replace your spark plugs as soon as you detect any issues.
  3. Catalytic converter – its role is to keep the environment safe from any harmful gases. In doing so, it can get hot really fast and can be a potential source of ignition.

What are other potential sources of sparks?


No smoking signs are there for a reason. You shouldn’t ignore these warning signs and you should never smoke or vape while pumping gas. That being said, you should never discard cigarette buds at the gas station either.

Even if you put out the cigarettes, all it takes is the slightest ember to cause combustion. If it’s particularly windy, hot particles of cigarette ashes can scatter around. If they fall close to the fuel tank, your car will burst into flames.

Cell phones

Even though cell phones are not nearly as dangerous as smoking, it is a good practice to stay off your phone while refueling. Simply, to avoid the build-up of static electricity. Leave your phone in the car and focus on refueling. Read our blog to find out how long it takes to refuel a gasoline car.

Other safety precautions to take when pumping gas

Always follow all of these safety precautions, just to be on the safe side:

  • Ground yourself first – Before refueling, make sure to ground yourself first to discharge the static on your body. Remember to also touch any metal part first before reaching for the gas pump.
  • Don’t get back into your car – When it’s really cold or hot outside, you might be tempted to leave the car on and get back into your car. Just don’t. Stay outside with the pump while refueling and switch the engine off.
  • Don’t overfill your car’s gas tank – Most gas pumps shut off automatically when the gas tank is full. In case the pump is faulty, always pay attention to the refueling process. Overflowing gasoline will cost you more money and can cause problems with your car such as damaging the canister. Also, find out how long gasoline fumes are flammable after the spill.
  • Keep gas away from your skin and eyes – If gasoline comes in contact with your eyes, flush them out with copious amounts of tap water for at least 15 minutes. Avoid rubbing your eyes and remove contact lenses if you wear them. If liquid gasoline hits your skin, it can cause severe irritation, so make sure you wash the affected area with lukewarm water and soap. Seek medical help if necessary.
  • Keep your children and pets away from the gas nozzle – they should never hang outside the car during refueling. While running around the car, they could easily knock into an active gas nozzle and cause you to spill the gas.

A person pumping gas.

How flammable is gasoline?

First, it’s worth mentioning that it’s very hard for gasoline in its liquid form to burn. It requires over 247° Celsius to ignite. The vapors that gasoline liquid gives off are what burns. Gasoline has a very low flashpoint of -23° Celsius. The flashpoint is the lowest temperature that will cause gasoline to emit enough flammable vapors to ignite in the presence of an ignition source.

Gasoline flammable vapors are heavier than air and can travel great distances from their source. Gasoline is a highly flammable liquid so always take diligent care when you handle, transfer or store it. If you need more tips on how to transfer gas safely from car to car, make sure to check our blog. In our blog, you can also find out which is more flammable – gasoline or diesel.

How to pump gas?

Pumping gas is a fairly simple and straightforward process. However, if you are a teenager, a new driver or you’ve always had a gas station worker pump your gas, you might find our step-by-step guide on how to pump gas useful.

  1. Locate the gas cap – The gas tank cap is not always on the driver’s side. There is a triangle-shaped arrow on your car’s dashboard near the gas gauge. It points to the side of your car where the gas tank is located. When you pull up make sure that the gas pump is on the same side as your car’s gas tank. Use the side mirror to check if you are close enough so that the gas nozzle can reach your car.
  2. Turn the engine off – Make this a good practice before you leave your car to pump gas. If your car has the button to unlock the metal gas lid, remember to use it.
  3. Open the lid – When you open the lid, on the side of it, you will usually find the information on the type of fuel your car uses.
  4. Choose the grade of gasoline – You can choose between regular, mid-grade, and premium. Unless you drive a sports car or a large SUV, you can stick to filling your car with regular gas. You can read more about why there are different grades of gasoline in our blog.
  5. Pick the right fuel nozzle – Once you’ve picked the right type of fuel, push the nozzle into the gas tank as far as it goes. When the tank is full, it will automatically shut off. Never put more fuel beyond this point, to avoid spilling.
  6. Put the nozzle back and place the gas cap back – Turn the gas cap until you hear a click and close the lid. Finally, pay for the gas.

How do you know how much gas to put in your car?

You can find the capacity of your car’s gas tank in your car owner’s manual. If you are pumping at the gas station, you don’t have to worry, as most gas pumps have a mechanism to stop the flowing of gas when the tank is full. You can always use a simple equation for fuel consumption, you just divide driven miles by the amount of gas used. 

Newer cars have a trip odometer that you can reset after you fill up your tank. It is typically located on your dashboard and you can set it to zero by holding a small button. When you set it to zero when you fill up your tank, you can simply check it when you need to fill it up again. It will show your mileage since the last time you bought your gas.

Final thoughts

We hope that we’ve managed to emphasize the importance of turning off your car’s engine every time you pump the gas. To be on the safe side, always follow all other safety precautions such as grounding yourself, avoiding going back in the car, and keeping gas away from your eyes and skin.

Always keep yourself and others safe while refueling. Our final answer to the question ”Can you pump gas with the car on?” is a resounding no. Pumping gas with your car on can result in a fire, or worse, an explosion, so it can become a matter of life and death. Learn how to put out a gas fire in case you ever need to handle this unfortunate incident.