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Winter Fuel Question

Most of today’s gas pumps provide fuel with ethanol in it already. Where I live in Wisconsin, it is customary to also put in some “gas line anti-freeze”. This stuff is just alchol of one sort or another. Is this still necessary or will the ethanol do the job already. I don’t want to duplicate unnecessarily OR damage the engine by running to much alchol in the fuel. I’ve heard to much can cause scoring and other heat problems; damage seals and reduce oil life.

What about it? Do I keep putting an additional $2 worth of this stuff in with every other full tank or not?


no need for any additional ethanol…whether gas-line anti freeze really works is an other issue

whether gas-line anti freeze really works is an other issue

There’s no question…it worked just fine…I can’t count the number of times I’ve seen it work.

The question today is…is it needed since ethanol is added…Probably not.

This question is asked a lot. The consensus seems to be that ethanol in the gasoline will absorb any moisture in the fuel system, rendering DryGas, Heet and similar products unnecessary.

A bottle of gas line anti-freeze once or twice during the winter months certainly won’t hurt anything, however, and might be good insurance, especially in Wisconsin.

A Wisconsinite now living in Minnesota, I have concluded that the added Heet is no longer worth it. Fuel systems are no longer open to the outdoors, except while fueling, so the amount of atmospheric moisure that gets in is minimal. Remember when gas caps had a little hole in them? That went away in, I think, the 1960s or 70s. And the ethanol that now makes up 10% of our fuel does about the same thing that Heet does - at no extra cost, except that it harms MPG. I think Heet is just throwing away money and I have not used it for decades.

Another factor is that fuel pumps now push the fuel (and whatever else gets past the in-tank sock) under high pressure to the fuel injectors, and excess fuel is returned to the tank. In the old days a weaker pump had to pull the fuel all the way to the carburetor. There was a lot less movement of the fuel, and that in some cases could contribute to freezing of any water that might be present.

It is important that moisture that gets into your fuel system is removed.  Any gasoline today (winter or summer) has additives including something to pick up any moisture.  No need for additional, normally.  

Don't Worry, Be Happy!

It’s possible that it may help – if the gasoline has been sitting around for a while, it may have already picked up a fair amount of moisture, and the ethanol MAY not be able to grab any more. As for “too much alcohol”, is dry-gas ethanol or methanol? I don’t know if that will have any effect on rubber seals and such. Best to check references/owner’s manual/dealer for maximum alcohol level that can be tolerated by a particular vehicle, and ask whether adding methanol (if that’s what’s in gas line antifreeze) makes any difference. Then you can start worrying about whether it will help with gas line freeze-ups.

Ethanol will absorb moisture. The problem with ethanol is, it doesn’t mix with gasoline very well and can phase seperate out of the gas along with the moisture it absorbs. This is why they don’t store gasoline and ethanol mixed together in the same storage tank at the refinery. Instead the ethanol is stored in a seperate tank and isn’t added to gasoline in the tanker trunk until it’s ready to deliver the fuel to the gas stations.

The fuel system anti-icing products sold are made of isoprophyl alcohol. Isoprophyl alcohol will mix with gasoline and will not phase seperate out of gasoline. So it’s ideal for removing moisture from the fuel system so it can be carried off and burned in the engine.

Ethanol in gasoline isn’t a problem as long as it doesn’t sit idle for an extended period of time. However if you allow E10 gasoline to sit for a period of time, the ethanol along with moisture it has absorbed will begin to phase seperate out of the gasoline. You then end up with a bottom layer water because it’s heavier than the ethanol and gasoline, a second layer of ethanol because it’s heavier than the gasoline, but lighter than the water, and a top layer of gasoline because it’s lighter than both the water and ethanol.

There’s the myth that moisture can’t enter today’s fuel systems because they’re supposed be sealed. That’s true if there’s never a leak in the fuel system. But how many Check Engine lights have come on because of a loose/leaking fuel cap or vapor canister system? Moisture not only enters the fuel system from the atmosphere, but also enters the fuel system from normal condensation from temperature changes. And I think the one that makes me chuckle the most is when someone states that,“Todays fuel systems are under high pressure.” That’s true as long as the engine is running. But once the engine is turned off the fuel pump stops running. So the fuel pressure bleeds off. So the fuel sits in the lines just like a carburated engine so it’s just as suseptable to freezing if there’s any moisture in the system.

So as long as you don’t allow E10 gasoline to sit around long enough to allow it to phase seperate, you shouldn’t have a problem with fuel system freezing. But if you’re going to let a fuel system with E10 gas sit for over a week, it would be wise to add a bottle of an anti-icing fuel system product that contains isoprophyl alcohol to prevent any moisture in the fuel system from phase seperating out of the gasoline.


There’s the myth that moisture can’t enter today’s fuel systems because they’re supposed be sealed. That’s true if there’s never a leak in the fuel system. But how many Check Engine lights have come on because of a loose/leaking fuel cap or vapor canister system?

And how many of us have filled up in the rain or snow???

The only way to get water in your gas tank today is to buy it from a vendor with major tank problems…Todays gasoline contains enough propane and butane to keep the vapor pressure up so NOTHING ever gets “sucked into” a gas tank, including outside air. There is no “condensation” in today’s gas tanks for that reason. Frozen fuel lines are largely a myth. If any freezing takes place, it’s the puddle of water in the bottom of the tank that freezes… But virtually no operational cars have a puddle of water in the bottom of their gas tanks, so lets just dump a can of “Heet” in because it FEELS GOOD, and at least you DID SOMETHING…

Thank you one and all. I believe you’ve answered my question about continuing to use the blue or red containers of “fuel line anti-icing” stuff. I think, that if I’m going to not move a car for a week or so, I’ll add some if it’s going to be below 10 deg. or so. Other wise, screw it and use the money for a nice cold beer!

I ask because I used to be a helicopter crewchief on UH-1C/M type helicopters and we got a LOT of water in the fuel systems overnight here in Wisconsin. The problem was rare in Viet Nam but we did find a bit of water now and then. More than once I found a pretty good amount of water running around in the bottom of the mason jar I used to pull a fuel sample prior to cranking while flying for the WI National Guard. (I HATE it when the fire goes out just as you clear some trees.) It’s kind of an Oh $hi% moment and your pilot always looks back at you funny because HE KNOWS it’s on HIS CHECK LIST AND USUALLY NEVER DID IT!!! He just expect his low-life enisted crew chieft to do it for him! Lazy bum!,… sir.

Anyway, thank again!

Jeff in Janesville, WI