Can you pump gas with the car on?

It is not unusual to find drivers pumping gas while the car is on, either accidentally or otherwise. If you are reading this, you have probably done so yourself and are wondering: can I pump gas with the car on?

Leaving your car on while you pump gas may not have grave consequences, but it is not a good idea. With hundreds passing through the gas station daily, one can start a fire or suffer the consequences of being refilled while it is still running. 

Although some said consequences are myths, there are possible dangers attached to doing so. This article will answer your questions on whether you should pump gas with the car on or not.

How flammable is gasoline?

Gasoline is a highly flammable and volatile liquid. Its flashpoint is about -23 degrees Celsius or 40 degrees Fahrenheit, meaning a match or a single spark can ignite gasoline without any problem. There is also the possibility of ignition on a scorching day.

The liquid gasoline is not very volatile and can not ignite without a catalyst, but gasoline constantly emits flammable vapors denser and heavier than air. The vapor is hardly seen but can stick around any open canister or gas station. Because of the highly volatile nature of gasoline, it is advisable to keep to specific rules when handling or pumping it.

Why is pumping gas with the car on dangerous?

Gas stations have safety signs suggesting you are in a danger zone and should avoid certain things to keep safe. Some obvious signs include no smoking, no flames, no phone calls, and turning off the engine.

While it is not entirely true that your car will burst into flames when you pump gas with the car on, it is also not impossible. Here are some possible consequences of filling your tank when the vehicle is on. 

Explosion

When you open the gas tank and place the nozzle inside, it allows the flammable gasses of the gasoline to escape. The more the tank gets filled, the greater their chance of escaping. As the car continues running, the heat and electricity generated by the vehicle can trigger ignition if it gets in contact with the liquid gas that splashes out or the gasoline vapor.

It is also possible that the automatic stop feature of the gasoline pump may fail and cause the tank to spill gas or overflow. In this scenario, the gasoline is more likely to ignite if the car is on. The odds of this happening are slim, but some real-life cases exist. 

Gas poisoning 

Pumping gas into a running car can incite harmful fumes into the air. These fumes can contaminate the air, causing health hazards such as irritation of the lungs, headaches, dizziness, and nausea. They can also increase the global warming index and damage the ozone layer.

Losing gasoline

When you leave your vehicle idle while pumping gas, it will continue consuming to stay on, resulting in unnecessary gasoline waste. You may be wondering – how much gas does idling use? Well, it might be more than you expect, so it’s also good to shut the engine off to save some fuel.

Losing money

Some newly manufactured vehicles have closed emissions control or fuel vapor recovery systems. Refilling your tank with the car on can causes the computer to register a P0455 trouble code. If this happens, you must hook it up to a machine to clear the code. The cost of doing this goes up to about $200 or more. It could also damage your vehicle’s fuel vapor recovery system (Evaporative Control System). It would take about $1500 to get it repaired by the mechanic.

Although the chances of these happenings are slim, they are not zero. The bottom line is that it is dangerous to pump fuel with the car on. You should ensure that you take precautions and shut off the engine to avoid possible consequences, except if you have a faulty starter that will leave you stranded if you turn it off.

Is it illegal to pump gas with the car running?

Pumping gas with the car running can be illegal or not, depending on where you live. In the US, you are never allowed to leave your car running while pumping gas; doing so can attract penalties. 

The International Fire Code, directed by the ICC, has been enforced to take care of such cases. Following the NFPA 70, the code says, “No internal combustion engine or electrical equipment fuel tank shall be refilled with a flammable liquid while the engine is running. Smoking and open flames shall be prohibited in areas where fuel is dispensed.

If you are caught by local law enforcement violating this, you will have to pay a fine. 

Can you harm your engine by pumping gas while it is on?

The short answer is no; since it only takes a few minutes to pump gas into your vehicle, there should be little or no damage to your engine. However, some factors can cause potential damage to your engine. 

If you accidentally leave the car on while pumping gas, there should be no problem, but making it a habit is risky to your engine. Cars with fuel-injected engines are less prone to damage from idling, whereas vehicles with carbureted engines should not be left idle for too long as this can cause overheating of the machine.

If the engine is not adequately maintained or has other issues, extended idling can cause damage to it. For most engines idling for about an hour or two can result in overheating.

Other things to do when filling up the tank

It would be best if you follow these precautions for your safety and others near you. Let us take a quick look at some of them.

No open flames

Since there shouldn’t be any spark while filling the tank, you should avoid open flames and smoke at the gas stations. These are the significant causes of fire explosions, and a slight flick is all it would take for the gasoline to ignite. You don’t want to experience a third-degree burn, do you?

Watch the pump

Never walk away from the pump when refilling your tank. While there is a locking mechanism on the pump to hold the stopper open and offer you a hands-free experience, you should always keep an eye on the pump while fueling. The locking system may fail, and the gas could spill on the ground, wasting the gasoline and increasing the chance of an explosion.

Use approved gas cans

When buying gas in cans, ensure that you use approved gas cans. You can use a red can for gasoline, blue for kerosene, and yellow for diesel fuel. Using plastic barrels or plastic bags to pump fuel in is very dangerous. It’s important to know the answer to the question “what color is gasoline” to make sure you are using the right substance.

No children or pets

If you have children or pets, ensure they remain inside the car while pumping. If they need to get out of the vehicle, it should be after you are done pumping and have pulled away the nozzle.

Our take

Shutting off the car is one safety precaution that should be adhered to at all times. Pumping gas with the car on is illegal in some places and could pose a significant danger to you and those around you. Whenever you need to refill your vehicle, ensure that you do not pump gas into the car when it is on.