How long before fuel goes "stale"?

[treg50]

I'm not going to use my car for 2 weeks. The tank is half full. Should I:

A) Fill up the tank now. (Does that reduce moisture build up?)
B) Fill it up when I start using it again. Ensuring the fuel will be "fresh" from the gas-station. (Does a half empty tank gather moisture in 2 weeks?)

Like I said I won't touch my car for 2 weeks, so do I have to worry about the gas going "stale" or moisture build up within 14 days?

[Weapon_R]

No worries. Gas won't go stale that quickly.

If you want, run it till E and park it. When you come to drive it again, just fill it up.

[Moe]

Most fuels when stored properly will last indefinitely. I imagine it is much the same for within your tank.

Suggestion:

Don't expose your car to the elements for those two weeks(avoid weather and temperature changes... in Calgary, almost impossible). Park it in the garage and you shouldn't have anything to worry about.

[GingeRRRBeef]

if you are too worried, just go to Canadian Tire and by fuel stablizers. Do they work? I have no clue.

[95TsiAWD]

The gas won't be as good after sitting in your tank for 2 weeks, with 1/2 a tank you'll get a good deal of moisture with the temp. changes we've been having lately. I don't think it'll be enough to make the car undriveable. Just take it easy until you use most of that gas up and then fill up with some premium. Or toss a little fuel stabilizer in before you park it.