What's the purpose of a pressurized gas tank?

[MrGone]

Just curious, what is the purpose behind pressurizing the gas tank? Is it for fuel ecconomy, emissions (like something to do with the charcol container), etc?

Thanks guys!
-Shawn

[Jeff92se]

Since when is it pressurized?

[MrGone]

when it was manufactured?

I'm talking about when you go to fill it up with gas and you get the phssst noise of the air escaping.

Just curious about it, Mustang doesnt do it (then again its mechanical pump and carb'd), I dont remember if the Durango, Scooby or Surburban do it either.

[Matt93SE]

Gasoline is a volatile substance.. it evaporates at a high rate, unless you pressurize the tank. (then it evaporates and liquifies again in equilibrium) that's where the pressure comes from.

[DanNY]

Originally Posted by Matt93SE

Gasoline is a volatile substance.. it evaporates at a high rate, unless you pressurize the tank. (then it evaporates and liquifies again in equilibrium) that's where the pressure comes from.

ding ding ding...da winnar!!!!

[MrGone]

So what does that mean if you dont get that pressure? Does it mean gas is just evaporating and not becoming a liquid again?

[harrymay]

all the cars ive driven, 84 chevy pu, 82 toyota pu, 96 tacoma, 88 celica, and my old old celica had it too (84) its pretty much to save your mileage as the gas evaporates and you start to loose it. also a safety precaution too, gas fumes are flammable. if its pressurized it save the pump, whether its mechanical or not from straining itself to hard.

[Matt93SE]

that means you could have a leak in the tank/hoses somewhere, you have a faulty cap, bad gas, lotsa things..

but at this point, it wouldn't surprise me if you've got a cracked hose somewhere and it's losing pressure that way. remember these cars are 10+ years old.

[subs1000w]

question if you eliminate your charcole canister what should you do with the hose coming from the tank that go the the CC

cap it off

vent it

hook it to intake maniphold