Wednesday, April 9, 2008

The Gas Secret

I don't know if these tips are real, but I am posting them anyway. You know, just in case:


� Only buy or fill up your car or truck in the early morning when the ground temperature is still cold.

Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role.

�A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps. � When you're filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3) stages: low, middle, and high. In slow mode you should be pumping on low speed, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money. �

One of the most important tips is to fill up when your gas tank is HALF FULL. �The reason for this is, the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount. �

Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up--most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom. � Hope this will help you get the most value for your money. � DO SHARE THESE TIPS WITH OTHERS!

10 comments:

John said...

all of this is true, but the difference is minimal 10 qts of gas heated 100 degrees will have the volume of 11.5 qts of gas so a 10 degree difference between morning and afternoon is only about
1.2% I don't think the temperature changes that much over the coarse of the day.

Karen Deborah said...

Totally amazing. I never heard of any of this before. I can't beleive you live in San Jose. I moved from Santa Cruz. you should come by and read my story about the earthquake in 89. You know the Good will down in Santa Cruz has some great deals. Small world.

HW said...

Great tips.

We will be making several trips to Indiana and back over the next several weeks, so they will come in handy.
I'm going to have my husband read this post.

Don Mills Diva said...

Wow - these are great tips - 1.2% is actually not a bad savings - I'll take what I can get...

Kristin.... said...

Thanks for stopping by my blog the other day! And awesome tips!

Emily said...

I read this yesterday and then dreamed about telling everyone I know that they HAD to do these things because gas was going to end up being $4 a gallon.

Astarte said...

Hell, anything that helps with gas is a blessing!!! I don't care if it even only saves me FUMES, because those fumes cost more than my lunch! My DH drives 90min each way to work, and even with his carpooling it's tough.

Susiewearsthepants said...

Gas prices are crazy. I am considering taking a second job to cover gas in my car. I already put my 16 year old to work. She gets her first paycheck this week and I am DONE putting gas in her car!

Anonymous said...

The comment about filling up when you tank is half full is probably not correct. A gas tank is sealed so there is no evaporation. Yes some of the gas turns to fumes with an air space, but it doesn't go anywhere. As the tank empties it's pulling a vacuum. The air sound you hear when you open the cap is fresh air running in, which then gets blown out with some fumes when you fill up. If you fill up on empty and only fill up half way, you are blowing a mix of fresh air and fumes back out, but not completely as you are not filling up all the way; therefore, you are retaining some fumes.

Although I'm not certain, I'm guessing the loss in MPG due to hauling around the extra weight of the top half of the gas tank exceeds the loss in fumes. Therefore, by only driving with your tank from 0 to half you are carrying less weight and get better gas mileage. I notice a very significant difference in acceleration from near empty to near full in my 4 cylinder vehicles.

Just something to consider.

Anonymous said...

The extra weight of carrying a full tank increases fuel consumption and lowers your gas mileage