:cat: Hi there everybody. When I suggested that we have a specific forum for fuel and petrol issues I was told that we don't need it. Hence, now we have some very good information about the specificity of petrol listed all over the forum. I copied this article from another site which may interest some of you.

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 thegasoline, 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, therebyminimizing 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 or HALF EMPTY. 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.

I've seen this on other forums as well. I think the only one with merit might be about filling-up when the truck is there. But then again, when have you ever heard of anyone having a problem from that.

Anyway, maybe this will be updated soon....
http://www.snopes.com/inboxer/household/gastips.asp

I've heard the same thing that aukland has mentioned. i have friends who own service stations and they've always told me to gas up real early in the morning if I could. i get up at 3 am to open the restaurants and i usually gas up then. his mentioning the vapor issue is correct about the slow mode. when I gas up my bikes, you wouldn't believe the amount of vapors come pouring out when you pump fast. ask anybody who rides and they will tell you the same.