Gas tank material
 

I thought this would be easy, but after a half hour of using google I gave up. Is the gas tank in the boxster aluminum, plastic, or steel? Reason I ask is a friend of mine said I should fill the gas tank completely before storing the car for winter to reduce the chance of rust developing on the inside of the tank. I told him it doesn't matter because the tank is either aluminum or plastic, but I can't find info to back up my case. So can anyone confirm what the gas tank is made out of? Thanks!

Black molded plastic..................... But rather than being concerned about rust, you should be adding StaBil to the fuel to keep it from going bad and screwing up your entire fuel system....................

Cool, thanks Jeff. I have used stabil in the past, but the car is isn't stored for more than 2-3 months. Probably not long enough to warrant the use of a fuel additive like stabil.

I'd still put StaBil in it, the fuel that is available today can come apart pretty quickly and the additive is really cheap insurance...... Porsche, by-the-by, has actually recommended using it year round as the result of problems they have seen. Normally, I'm the last person to agree with them on most things, but this is one that really can do not harm.............

You're probably right. It couldn't hurt and it might help clean out any deposits. I'll add some stabil to it soon.

Just be sure to run or drive the car for about 15 min. after adding so it circulates thru the entire fuel system............

The other reason to fill the tank is to keep condensate from forming and mixing with the gas. Especially if your fuel has enthanol in it.

Also a reason not to run the tank dry as water is "heavier" than gas.

[QUOTE]Also a reason not to run the tank dry as water is "heavier" than gas

- Why the quotes?

He probably means something along the lines of mass vs. weight, as they are not really the same thing. But most people just think of it as heavier, so its easier to say that.

Water is more dense than gasoline. When it separates from gas, it settles to the bottom of the tank. The fuel pick-up is located near the bottom of the tank. Any water that separates from the gas will be pulled into the fuel system whether the tank is empty or not.

The reason that keeping the tank full is a good idea is to keep the amount of air in the tank to a minimum. Air has a harder time keeping water in suspension than gasoline, so when the temperature of the tank drops, more water will fall out of suspension from the air than it would from the gas. Gas can and does hold water in suspension but can only hold so much at any give temperature.

Most all gas tanks today are molded high density or linear low density polyethylene.
It should be stored as full as you can get it and stabil will also help emulsify and suspend any water in the tank.