Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE Membership sticker when you sign up for a Premium Membership and choose the recurring plan.

how long b4 gas goes bad

Discussion in 'The Garage' started by SHAWNSTER, Jul 17, 2006.


    SHAWNSTER 1/2 ton status

    Sep 24, 2002
    Likes Received:
    I got this 62 caddy that has been sitting for about 6 years-4 years ago they drove to get a new battery and filled up the gas tank-they drove it 4 times that month and parked it - i am debating droppin the tank, but wonder if it is bad-it has 3/4 of a tank now-my friend says maybe fill up w/ premium and some sort of fuel treatment-what do you all think????
  2. blazinzuk

    blazinzuk Buzzbox voodoo Premium Member GMOTM Winner

    Dec 20, 2002
    Likes Received:
    Afton / Star Valley Wyoming
    This may not be the right answer but here goes. I have started a couple of old cars that have been sitting for a long time and I have never changed the gas. I get a couple of cans of any fuel system cleaner and run that through on the old gas and the first 2 tanks of new gas. I also change the filter before I try to start the car fuel filter that is.
  3. diesel4me

    diesel4me 1 ton status Premium Member

    Jul 24, 2003
    Likes Received:

    We had several vehicles at the junkyard sit for at least 2 years with old gas in the tank--we either cut the fuel line and used a gas can with fresh gas to start them up to see if the motors were worth selling,or we just crossed our fingers and used the gas in the tanks..most of the time the gas stunk like it was stale,but the cars ran ok anyway!..

    Blazinuk is right,we just added some high octane gas or "Sta-Bil" to the old stale gas,and they ran a bit ragged until the old gas was used up,and a gas filter clogged up once in a while,sometimes the float needle in the carb would stick,and flood it out..but for the most part,we were suprised how well the cars ran on crappy stale fuel,considering how long they sat--WATER in the fuel was more problematic than just stale gas..Dry-Gas is helpful for getting the water to burn with the gas--Isopropanol alcohol works the best..

    I'd guess anywhere from 3 months to 3 years is how long it takes for gas to get rank and go stale..todays "oxogenated" fuel goes bad much faster than the gas of past years..

    I bet 90% of the cars at the junkyard had 90+ octane leaded gas in them,since most of them were 80's and older models...maybe thats why we didn't have too much trouble with it..we drained a lot of gas tanks and used it in out own vehicles,after a crude "filtering"..we poured it thru a nylon stocking,then let it set in a large barrel to let the water settle to the bottom--then used a siphon hose to siphon it from the TOP of the barrell..and learned to NOT use the last 3" or so!!..:crazy:
  4. miniwally

    miniwally 1/2 ton status Premium Member

    Aug 11, 2003
    Likes Received:
    I won't say if the gas is good or bad but I know this from my Snowmobiling.

    When we are running mod sleds with high compression motors we always leave the tank full with stabil in them for the summer then drain the gas and put in new gas in the Octane rating needed for the motor. Usually 104+ race gas.
    The snowmobiling world is claiming that gas begins to loose octane in 30 days of sitting. That is why we run very fresh gas.
    With todays fuel additives I would change the filter add some octane boost, fuel system cleaner and fire it up if it was me.
  5. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Dec 14, 2001
    Likes Received:
    Pleasanton, CA.
    Gas starts to go bad after only about 6 months. If you try to use old gas you're only asking for troubles. I can tell you what can and probably will happen if you want, PM me and ask any questions you want. I don't feel like posting in here as just about any time lately that i give my professional opinion (20 years) people want to argue with me about it. I'm almost at the point of not wanting to help anyone anymore because of it.
  6. fabjunkie

    fabjunkie 1/2 ton status

    Aug 23, 2005
    Likes Received:
    Dallas Outskirts
    I'm with the guys on putting some octane booster or the like in, change the filter and go. I've ran several cars on gas that was way over the 6 month mark and haven't had problems with any of them.

Share This Page