Gas shelf life. High test VS 87 octane.

Discussion in 'The Pub' started by retrobob, Jan 29, 2015.

  1. retrobob

    retrobob Member

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    So I'm guessing higher octane gasoline has a somewhat longer shelf life?

    Or does higher octane have nothing to do with the shelf life?
     
  2. Trotter

    Trotter Supporting Member

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    Around here, the higher octane gas doesn't have ethanol mixed in... It stores better than the 87 w/ ethanol with less risk of your fuel lines/filter getting gummed up.
     
    Last edited: Jan 29, 2015
  3. Dr. Tweedbucket

    Dr. Tweedbucket Deluxe model available !!!11

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    I'm glad you asked that question :red

    The high octane gasolines will not store any better then regular 87 octane.
    This could have been true in the old days when the additives used in the higher octane's made it more stable but not any more, and that was the additives, not the higher octane that did it. :waiting
    Gas with methanol isn't good either, so as above if your hi-test has none, it will possibly last longer. Also note, using a different the recommended octane by the engine manufacturer can cause a LOSS of performance in said engine. Higher octane IS NOT higher quality. Octane is simply that fuels resistance to auto-ignition in the combustion chamber. Too high octane and you'll loss power through inefficient combustion eventually leading to fouled plugs and increased deposits, to low of octane and the fuel will auto-ignite and the loss will be from the ignition happening at the wrong time in relation to the pistons position (inefficient due to timing) it will also cause damaging pressure increases in the cylinder and that pinging sound (caused by the flame front of the self ignited fuel hiting the flame front of the spark ignited fuel, and very high engine temps. :fisticuffs

    Best for storage is to start with fresh gas (almost every major brand with proper storage will last 1 year without treatments), store it in a proper place where the temps will remain as steady as possible (i.e. NOT in the sun) and in steel containers, some plastics will break down with long term use.:nono
    The top fuel stabilizers should keep the fuel "fresh" around 5 years if retreated once or twice a year (or per instructions).
    Again proper storage is the best thing you can do for your fuel, indoors (obviously an outbuilding or shed) where temp changes are gradual and preferable 80º or less.
    I had a lawn mower sit a good 5-6 years in my basement (heated/cooled).
    When a friend needed to borrow it I checked the tank, it was a little darker but looked good, no corrosion, no dirt so I figured I'd try. Started and ran good, no problems.
    Being a gear head and owning an antique vehicle I know about long term storage. Myself, I never use anything. :bong I put my car 'away' for the winter anywhere from late November to late December (I drive it until they start throwing salt <the white death> on the streets, and take her out again (regularly) in mid March. Some times I take it out in January or February if it hasn't snowed in a while and the salt has washed away, but that's usually under 50 miles. Obviously with the 3/4 to 7/8 tank of gas that's in there in November doesn't need replenishing (20 gal tank) until late March thru mid April, about 5 months, never a problem and that's even with the reformulated crud (another note, if you can use NON oxygenated fuel for storage, it'll hold up better) I've heard good and bad about Sta-bil from others, but nothing bad about Power Research Inc (PRI) additives. Supposedly they've tested that stuff as long as 10 years and the gas was still good. Obviously it was probably under perfect conditions. :red
    Again, I do not need or use additives so I can't vouch directly for either. There is a couple other brands I've heard about but do not recall the names, small companies though. Sta-bil and PRI are the two biggies I guess. I know you don't care and you aren't even reading this any longer, but if there is anything else you want to know like starting fires with gas, well high test works better because it blows up slower so you can get away without frying your eyebrows off. :peenut
     
  4. Peteyvee

    Peteyvee Premium Platinum Member

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    Damn Tweedy, I'm impressed. Seriously... :aok
     
  5. GAD

    GAD Wubbalubbadubdub Silver Supporting Member

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    Go to the airport and get the good stuff. :)

    I use Pri-G for storage, which is awesome.
     
  6. Peteyvee

    Peteyvee Premium Platinum Member

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    We used to do that for our muscle cars, but they stopped selling it to us unless we could prove we had a plane. There are still two gas stations in town that still sell 102 octane (or maybe it's 104?) as "racing fuel"...
     
  7. stephenf

    stephenf Member

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    100 octane avgas will indeed wake up your vintage muscle car. But don't use avgas in any vehicle with a catalytic converter because the lead in avgas will destroy that converter.
    While mogas is a result of refining oil, avgas is a blend of various petrochemicals. These components serve to extend the shelf life, reduce detonation, and eliminate vapor lock. If you dip your finger in car gas, it will stink all day. Dip your finger in avgas and the liquid will have evaporated before your finger reaches your nose.
    The airboat operators on this side of Florida have no problem buying avgas for their airplane engine powered rigs.
     
  8. '58Bassman

    '58Bassman Member

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    The Octane rating drops over time, but tat doesn't mean gas mixed with ethanol will be usable after the ethanol has attracted water. It experiences what's called 'phase separation' and this looks kind of milky, settling at the bottom. It's almost useless and is hard to deal with, especially in fuel systems that don't pass water.

    I worked for two boat dealerships and had many boats come in with bad carburetors. It was more efficient to have them rebuilt and I asked the guy at the carb shop about the gas, which had MTBE. He said it started to go bad in about 20 days, depending on conditions. If it's in a sealed tank, like most cars and trucks, it takes longer but in boats, which have vented fuel tanks, it starts going bad almost immediately.

    Adding fuel stabilizer after it starts to go bad is useless and won't reverse the degradation.
     
  9. '58Bassman

    '58Bassman Member

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    And doesn't bad gas have a truly distinctive odor? I had to work on a boat that the owner said needed a tuneup. I got to work that day and as soon as I stepped out of my car, I smelled the bad gas. Turns out the boat sat for three years without being put up properly. He had tried to start it and it would occasionally fire, but never ran. I put my timing light on it and it would start out fine, then the timing mark would jump all over the place. I checked everything and finally, removed the distributor- the gear had gotten wet and some of the teeth were missing. I never tried to run it on the gas in the tank, I used a tank from an outboard motor.

    I used to go camping with some friends and invariably, it would rain. Didn't matter that we were in the middle of a dry spell, it would rain. We all have Coleman lanterns and camp stoves, so we always have White Gas. Usually, we have about 3 gallons of it and when the wood got wet, in spite of anything we did to prevent it, we'd put the logs in the fire ring, douse it with White gas and light it. Once the water had burned off, we'd douse it again and get on with cooking our breakfast or dinner.
     
  10. Dr. Tweedbucket

    Dr. Tweedbucket Deluxe model available !!!11

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    I've sniff tested hundreds of brands, I KNOW gasoline! !11 :red


    Yeah, bad gas breaks down and smells like crappy ol varnish. I really wish we had the good stuff of yesterday. SuperShell used to be pink and man did it ever make my car run good! :love:
     
  11. Pietro

    Pietro 2-Voice Guitar Junkie and All-Around Awesome Guy

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    NOS Gasoline... the next big thing...
     
  12. RhytmEarl

    RhytmEarl Member

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    There was a 76 station in Pasadena that sold >100 octane gas. IIRC it was north of $7/gallon.

    https://www.google.ca/maps/@34.1278...ata=!3m4!1e1!3m2!1sI0-kcxem79O4W6uorTeebg!2e0
     

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