A Costly Mistake at The Gas Pump You Can Avoid!
By: Scott Siegel

The costly mistake many drivers make when filling their car with gas is to overfill it by topping it off. When the gas pump nozzle clicks off, do you stop or do you keep pumping? Are you trying to add more gas your tank after the shutoff trying to stuff as much in as possible? Are you pumping more gas after the shutoff to round your total cost to the nearest full dollar amount? If either of these scenarios are true, or if any other reason causes you to top off your tank you have developed a bad habit that is costing you money and is contributing to air pollution.

Most gas stations are equipped with pumps that have vapor recovery systems to recover gas vapors keeping those vapors from getting into the air. If you top off your tank it will cause you to pay for gas that is drawn back into the gas station's vapor recovery system.

The extra gas you are trying to pump into your tank may just be drawn into the vapor line and back into the station's tanks. That means that you will be paying for gas that is not going into your car but is going back into the gas station's storage tanks. Of course the effect of this is to raise your cost of gas.

When you top off your tank there is a good chance that gas will evaporate or will be spilled on the ground. Both of these things will cost you money for gas that is not getting into your tank. That is it bad for your wallet.

There are more bad things that can happen when topping off your gas tank. Gasoline expands as it gets warmer. This is certainly important in the summer or in climates with warm weather. Gas in the station's underground tanks will be cooler than the air. As the gas in your tank warms up it expands. As the gasoline expands it needs more room.

If you overfill your car, there is no room for the fuel to expand. As the gas expands it has to go somewhere. It could easily find it's way into the vapor collection system of your own car. This may foul the vapor system causing it to malfunction.

The fuel that expands is lost gasoline that you have paid for. You paid for gas that you are not able to use. The result: your cost of gasoline goes up. But that is not the end of your increased costs! If the expanding fuel ends up in your car's vapor collection system it will negatively affect the system. If that occurs your vehicle will become much less efficient.

A vehicle that runs inefficiently burns more fuel which translates into spending more money on gas. That is a double hit in the wallet, once for the fuel that is lost directly and second for the additional gas your vehicle uses because it is running inefficiently.

Gas vapors are a major factor in adding toxic pollutants such as benzene to the air. This contributes to bad ozone days. Gas vapors are bad for your health and harmful to breathe. When you top off your tank you will end up with vapors released into the air. When this happens you are breathing in toxic fumes.

The next time you stop to fill your vehicle, when the pump stops don't try to add any more gas, your tank should be quite full. Don't overfill it! Don't top it off! You will save yourself fuel and money but you will also contribute to preserving your good health and preserving the environment!

 

I'm aware of this.

 

I luv your sig....lol

--"Paint may car Oscar, I want it back...You !@#$%"--

 

This is something that I have to be careful of down here since everywhere is full service by law, but I routinely ask to fill it myself (claiming it is a unique vehicle and one needs to be careful in how they fill it, which is garbage, but usually works).

 

is it also true that you will get your money's worth of gas by not pumping gas with the handle fully pressed and to have it at half way instead?

 

Well having it at a slower speed means the gasoline won't splash as hard so less of it will become vapour. It's preferred that you push the nozzle in, then let it rest so that the gasoline can flow down the sides of your fuel filler pipe into the tank, instead of falling in like Niagara Falls (and we know how much spray that causes).

 

people who top off get on my nerves. and also, when you top-off a newer OBD-II car with an fuel evaporative emissions system, you could force fuel into the carbon cannister/EVAP valve module and trigger an costly CEL.

 

.... I've been working in a full serve gas station for 5 years and I've seen the nozzles, hoses etc and filled thousands of cars, never noticed there's another hole other than 1 big one for fuel to go into your car, I've also looked at the twist section, there's only 1 passage...

Vapor recovery, not here we don't have..... unless somehow they've changed the pumps and nozzles without me noticing and somehow can get another passage on the twist part, which is almost impossible.... I don't think they've got their sources right....

Also, on a hot day (30ish'C), when you fill up, you can see the vapors coming out when you put the gas in, the vapor comes out from the gas filler hole and flows down by the side of the car as vapor is heavier than air, it flows to the ground.

The mechanism that makes the click off is a metal rod that extends from the tip of the nozzle to about the handle and once gas flows up and its pressure (sometimes just pressure as vapor can't escape fast enough from the tank makes early click offs) hits the rod, it clicks off.

The hose part is just... well a hose...

I worked in a Chevron (Texaco in the states) and noticed the nozzles are made by Husky

I don't know if there's another type of design out there, but as I see it from driving to and from Vancouver and Winnipeg a few times, the nozzles are roughly the same everywhere.

 

That article is so poorly written it hurts my head.

 

hey i learned this in smog class lol i always stop at the click anyway.

 

Another common error is filling up while the tanker truck is pumping gas into the underground tanks. Always wait for at least 5 minutes after the truck is done and shuts off the valves. Otherwise, the turbulence of the gas going into the underground tanks (particularly if they are old) stirs up dirt, water, and sediment from the bottom of the tanks, and where does that stuff go? Yep.....right into YOUR tank. Filters in the gas pumps and your own car are supposed to prevent that stuff from reaching the engine and fuel injectors, but they can get clogged up.....and you engine will not start or run properly.

 

If that's true, that's a lot more interesting than an article about not topping off your car--hahaha. I never even thought about your point...

 

Chevron is from the states - mostly concentrated on the West Coast.

 

ah I remember now, I've filled before in USA's Chevron... somehow though it's only canada as all I see was Chevron Canada's stuff when I work... why though? just west coast calling Chevron? While it's Texaco's why not just 1 company to save expenses?

 

Chevron and Texaco are the same company, they were known as ChevronTexaco, but went back to Chevron 2 years ago.