What gas Mileage do you get?

[bratgrl]

Someone once told me the gas needs a place to expand & contract, but I dididn't buy it then, I can't think of a reason to buy it now. The guy who told me was the guy who worked at the gas station, and he had a funny haircut.

My owner's manual says not to "top off" the gas tank for the same reason. I think the guy who wrote the manual had a funny haircut too.

[Davalos]

My owner's manual says not to "top off" the gas tank for the same reason. I think the guy who wrote the manual had a funny haircut too. [/color]

 

Heh heh ... Oops! I forgot to read the manual! Anyway, yeah, I just looked at the guy and said "Yeah? Expand THIS!", did my gesture, and then got outta there before he called the cops...

[robm]

Gas DOES need some head room to expand. It comes out of the ground at about 50 deg. F, and then sits in a gas tank at temperatures up to 100 deg. F. It is going to expand. If there is no head room, it will dribble out the fuel filler nozzle. We are so cheapo we are concerned about fuel mileage, there is no sense in letting it drip on the ground.

[DaveT]

Gas DOES need some head room to expand. It comes out of the ground at about 50 deg. F, and then sits in a gas tank at temperatures up to 100 deg. F. It is going to expand. If there is no head room, it will dribble out the fuel filler nozzle.

 

+1

 

And it can also get backed up into the evaporative emmissions system. One of the manuals stated that this was not a good thing to do. (I came across it years ago)

[beataru]

About the Topping off thing "THE GENERAL PUBLIC NEEDS TO UNDERSTAND THIS!" It can harm the environment if your driving a 80's jeep! but what it really does is overfills into your charcoal canister and ruins it so your not getting any more gas into the tank, its being absorbed.