Gas Tank: Necessary to keep at least half full in winter?

Discussion in 'Off Topic' started by johnjohn320, Apr 17, 2009.

  1. johnjohn320

    johnjohn320 Diamond Member

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    I've been told it's a good idea to keep your gas tank half full when temperatures outside are above freezing. Any truth to this? Why is it true, if it is?
     
  2. hanoverphist

    hanoverphist Diamond Member

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    condensation could freeze? thats the only thing i can think of...


    here in az i dont do anything different, but when my mom stores her harley for the summer (shes a wuss and wont ride in 110 deg lol) she and the rest of her merry club fill the tanks full to keep the condensation from causing rust
     
  3. 0roo0roo

    0roo0roo No Lifer

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    um the only reason i've heard is that being very low can wear on the pump because it uses the fuel to cool it or somethin like that. but that would apply year round.
     
  4. alpineranger

    alpineranger Senior member

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    I guess because when it freezes the volume will decrease, if it decreases too much you could have problems (fuel starvation, overheating fuel pump, etc). In that case, it wouldn't need to be half full, just don't keep it too low.
     
  5. Zenmervolt

    Zenmervolt Supermoderator<br>The Garage<br>Elite member

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    It's more of a holdover from when people didn't have cell phones and there was the potential to be stuck on a country road in the snow. In that sort of situation, you'd want to have enough gasoline to keep the heater going for a while.

    It's similar to the "rule" for boating: 1/3 of the tank to go out, 1/3 of the tank to come back, and 1/3 of the tank for emergencies.

    ZV
     
  6. Bignate603

    Bignate603 Lifer

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    I agree, it's not really a requirement for the car itself. It's just a good idea.
     
  7. WTT0001

    WTT0001 Golden Member

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    Rumer has it that you should keep it at least half full when it's below freezing. Something to do with condensation = a frozen gas line. Drygas also helps.

    WTT
     
  8. rbV5

    rbV5 Lifer

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    This Rumer fellow is full of crap;)
     
  9. BoomerD

    BoomerD Lifer

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    Keeping your gas tank full during cold weather helps to eliminate condensation in the tank.

    If your car has an in-tank fuel pump, you should always keep the tank 1/4 full because the gasoline both cools the pump and lubricates it...this is why many cars have to have the fuel pump replaced if they run out of gas...the fuel pump burns up fairly quickly when it's run dry.

    No "rumers," no "old-wive's tales," just automotive facts.

    (I'm surprises that ZV didn't set youse kids straight.)
     
  10. Red Squirrel

    Red Squirrel Lifer

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    I always keep it at least half full for several reason. The main one is condensation, the second is if for some reason I have trouble starting my car and need a boost, I'll have enough gas to let it running for a while to charge the battery.
     
  11. DrPizza

    DrPizza Administrator Elite Member Goat Whisperer
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    If I recall reading correctly, condensation is much less of an issue with pressurized systems. Also, gas is formulated slightly differently in colder climates to help eliminate problems such as a tiny bit of water in the tank. 20 years ago, lots of people carried dry gas with them in the trunk, just in case, and a lot of people would add it to the tank at each fill. Now, I can't recall even seeing it for sale that often.

    Also, the magic number: "half a tank" - if the tank is half full, you'll still get 2/3's as much condensation as if the tank was 1/4 full.
     
  12. zCypher

    zCypher Diamond Member

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    In Quebec, it can be relatively cold, but I've never had any problems with my older (80s) or newer (00+) vehicles with full, half full or almost empty gas tanks. I guess it's just to be on the safe side, to put less strain on the components mentioned above and to avoid any potential getting stuck running out of gas when it's freezing outside. So no, I definitely wouldn't say "necessary" to keep at least half full in winter, especially if your winters are not that intense. It definitely isn't a bad idea though.
     
  13. Zenmervolt

    Zenmervolt Supermoderator<br>The Garage<br>Elite member

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    I did.

    I run my cars down to the low fuel light every tank and never have a lick of trouble. If you completely run out of gasoline, and leave the ignition on for a long time after the engine stalls and you do this repeatedly, then it can cause issues. The 1/4 tank "rule" is a superstition. Keep up on the proper intervals for the filter and don't run the tank bone dry and you'll be fine.

    ZV