What are the effects of pumping gas with your car on and why are we told not to do it?

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I have a cousin that is part of law enforcement (he’s sort of like boarder patrol) and he said that while shadowing a superior that he learned that, because of his job, he should pump gas with his car on and it had just become a habit for him. I thought that was a big no no for fire hazard reasons. What else is bad with that?

In: Engineering

6 Answers

Anonymous 0 Comments

All it does is throws off your MPG reader and over a long time MAY cause a vacuum seal failure. No fire risk. Cars should not shoot out flames or sparks with normal use lol

Anonymous 0 Comments

It CAN cause a fire. Just because it usually won’t, doesn’t mean it is safe. When dealing with flammable liquids, don’t take chances. Even police should turn their vehicles off. They have to obey the same laws as the rest of us.

Anonymous 0 Comments

Your car’s gas tank has an evaporative system. The system allows pressure inside your gas tank to be relieved by sending excess pressure into your car’s engine intake so you don’t ven fuel vapors into the atmosphere which is a key contributer to smog. The system also allows air from the atmosphere to enter the tank while gas is being burned so the tank does not collapse when fuel is constantly being sucked out by the engine. Your car very carefully measures the amount of air that it let’s in from the atmosphere and vents into the intake while it’s running. It can’t do this when the gas cap is off and air is constantly being displaced by gas being pumped into the tank.

Anonymous 0 Comments

Common belief is that it’s a fire hazard, but that’s not true. The only thing that’s exposed to the air that’s hot enough to ignite fuel vapors outside of the combustion champers would be the catalytic converter, and that’s only inside of it. So the chances of your catalytic converter creating a fire due to filling up with gas while it’s turned on are pretty much zero. The biggest cause of gas station fires is static electricity. If you want to be safe, just discharge yourself by touching something metal before you touch anything near the filler/nozzle.

The only reason you should turn your car off is to save fuel. There’s no reason it needs to be running while you’re not in it. You’re just wasting fuel.

Anonymous 0 Comments

Think of it like eating while taking a sh!t. Kind of counter productive; the car is using fuel to run and you are trying to fill it up. Some think that turning the car off and on again uses more fuel than just leaving car on while fueling. This might be true for deisel vehicles, but it is not true for gas vehicles.

Anonymous 0 Comments

It is a fire risk. It’s a much lower risk now than it was with cars of the 60’s and 70’s, but it’s still a risk.
To be honest I don’t see a single advantage in doing it. It wastes fuel and the second or two it takes to start your engine in unlikely to make any difference. Many cars now automatically turn their engines off when stopped and restart when you take your foot off the brake. This does may a difference to city MPG and reduces pollution.