|Originally posted by Tony Kania:|
The Fiero has a very specific tank shape. It allows for the maximum amount of fuel to be stored within the dimensions available. I have no doubt about there being alternatives to an OG tank, but I would initially assume that other available tanks that fit within the dimensions available are slim.
Good point... the real question is, is the new tank as big as the factory tank?
Supposing we're talking about polyethylene, it can be cut and welded (using polyethylene filler rod). So a slightly larger tank of approximately the correct dimensions could be made to fit like a glove.
I suspect that plastic fuel tanks are fluorinated; the tank is probably filled with fluorine gas (chlorine might work too) while it is still in the blow molding machine. This halogenates the plastic molecules, making them less porous, or more gas-tight.
I have a crappy plastic jerry can that always smells of gasoline, even when the cap is on. No actual dripping though. I suspect that it wasn't fluorinated.
At the places where you cut and weld, you would lose the fluorination treatment. For a project car, I don't think this would be an issue, but if you were trying to test a car for evaporative emissions, that might be different...