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?isopropyl alcohol

I am a firm believer in the use of isoprpyl alcohol in fuel systems to prevent winter driving issues.Recently I've heard that with todays blend of ethanol gasoline that this is no longer recommended/or may be harmful. What is your thought?


  • edited December 2010
    I've been driving since the mid '80s (admittedly not real long), and I've never had winter fuel system problems, even in 0 F weather with a carbureted car. These days, I think they've got all the fuel additives right at the pump, and modern fuel injected cars are much less of a hassle in the winter.

    Some types of alcohol (particularly methanol) are very corrosive. I wouldn't put isopropyl alcohol in my fuel and risk harm trying to fix a nonexistent problem.

    I think this is another case of trying to deal with a problem in 2010 that hasn't existed since the 1960s.
  • edited December 2010
    We don't have ethanol blend gas but today's gasolines have many additives and a smalll amount of moisture is of no concern.

    However, in very cold weather ( subzero), and when I have to park in an underground heated garage, I still put in a small bottle of "gasline antifreeze" per full tank.
  • edited December 2010
    You are probably referring to back in the days when carbs ruled the earth, and cars experienced carb icing under cold conditions, along with high humidity conditions. Typically, most heat riser systems on carbs either were disconnected, or didn't work very well. Alcohol was added to help prevent some of the carb icing, but never resolved the issue entirely.

    If you have a car with a fuel injection system, this isn't an issue anymore.

    This still occurs with some motorcycles that are ridden in cold, humid conditions, that have carbs. Some bikes allow you to retrofit a carb heater kit to try to help with the issue. Those don't always work either, however.

  • edited December 2010
    If you buy gas with 10% ethanol, you don't need the isopropyl alcohol. Google "Dry Gas Wiki" for more on this for a view subject to scrutiny.

    Before 10% ethanol gas arrived I never used isopropyl alcohol anyhow and never had a problem with a frozen fuel line. I have lived in the upper midwest US since Hector was a pup.
  • edited December 2010
    Back in the carburetor days, my son had taken my 1978 Oldsmobile to college. I had admonished him to not let the gas tank go below 1/2 full in cold weather, but I knew he wouldn't take my advice. At any rate, one evening when the temperature was around zero degrees Farenheit, I got a telephone call. He had driven the car less than a block off campus and it quit. He called the motorclub service that I had purchased for him and had the car towed back to campus. The wrecker operator said that his fuel pump was probably shot. Well, my son didn't have the money for that repair. I told him to go down to a store off campus and for $1 he could purchase some gas line antifreeze to pour into the tank. I suggested he wait until the temperature got above freezing to attempt to start the car. Well, he didn't wait that long. Two days later, when the temperature hadn't gotten above 20 degrees Farenheit, he managed to start the car. He was elated, particularly because he bought the cheaper gas line antifreeze for 49 cents. One of his classmates had the same problem and my son advised him to buy gas line antifreeze. This fellow worked in the horse stable at the college and wanted to shovel warm horse manure under the tank to warm it up. My son thought that it was worth 49 cents not to stink up the car.
  • edited December 2010
    In addition to the other valid information provided thus far, namely that the OP's belief is unfounded in light of the presence of ethanol and the reality that isopropyl alcohol could damage the fuel system, there is another hole in the OP's theory that is wide enough to drive the proverbial Mack truck through it.

    Bryan--unless you have access to "industrial strength" isopropyl alcohol, you are likely using the same stuff that most of us buy in the supermarket or the drug store. Do yourself a favor and look carefully at the label. Most isopropyl alcohol is "70%" strength, and if you want to opt for the more expensive stuff, you can buy "91%" isopropyl alcohol.

    Do you know what the other fluid in that bottle is?
    It is WATER, to the tune of 30% by volume or 9% by volume, depending upon which variety of isopropyl you happen to buy.

    So, that leads to the inevitable question:
    How do you imagine that you can "prevent winter driving issues" if you are actually adding water to your gas tank?
  • edited December 2010
    Pure isopropyl alcohol is excellent in removing moisture from the fuel system. This is because isopropyl alcohol absorbs moisture and doesn't phase seperate out of gasoline. Ethanol also absorbs moisture. But the problem with ethanol is that it phase seperates out of gasoline. So if you have stored gasoline with a 10% ethanol contant, and any condensation ocuurs in the storage container, the ethanol will absorb this moisture and then phase seperate out of the gasoline causing the ethanol and moisture to settle to the bottom of the storage container. which results in corrosion.

    This is why you find isopropyl alcohol in products such as Iso-Heat and Seafoam.

  • edited December 2010
    You're right. Hopefully, the OP is referring to Dry Gas or Heet formulations using isopropyl (not methanol).

    Back in the day, when tanks were vented to the atmosphere, carbs ruled the earth and gas stations seemed less well regulated, fuel line freeze ups seemed fairly commonplace where I lived. I once had several 1-2" long icicles shoot out of my disconnected fuel line. Back then, Heet or Dry Gas were sold commonly right at the pump. With today's closed fuel systems, fuel injection and ethanol blended gas, those additives are no longer necessary.
  • edited December 2010
    If gas in your area is E10, and it seems that is the most common fuel out there now, then no need to add more alcohol. There is alcohol in your gas tank already. I don't see how adding a bit more can hurt, but why?
  • edited December 2010
    For years you could buy two kinds of Gas Line Antifreeze. The common less expensive products were made of methyl (methanol) alcohol. The more expensive type was made of isopropyl alcohol.

    One winter back in the early 70s, I got stuck up in Montreal Canada during a cold snap (-40 overnight lows). Many were pouring rubbing alcohol into their gas tanks as a form of gas line antifreeze.

    With today's ethanol fuels, the need for gas line antifreeze is rare.

This discussion has been closed.