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View Full Version : Preventing Gas Line Freeze. Is it better to buy gas with or without 10% Ethanol?


WhipperSnapper
01-24-2011, 10:45 PM
If you want to prevent a gas line freeze up, is it better to purchase gasoline with or without 10% ethanol (assuming that you have a choice)?

Would adding a bottle of gas line antifreeze (say, HEET) with every tank harm the engine in any way?

LTC8K6
01-24-2011, 10:57 PM
You should not need any anti-freeze additives with quality fuels, 10% ethanol or not.

The Boston Dangler
01-24-2011, 11:04 PM
in EXTREME cold diesel can thicken up, but i've never heard of gasoline freezing on a land vehicle.

Eli
01-25-2011, 12:04 AM
Heet is alcohol. Fuel with 10% ethanol should have a considerably lower freeze point than regular gasoline.

Based on a quick Google, gasoline has a freeze point of -40ºF. I don't know if that's for 10% ethanol blends or not. Ethanol has a freeze point of -173ºF.

Where do you live? Alaska?

WhipperSnapper
01-25-2011, 01:13 AM
I think the danger is that you happen to get bad gas you can get water in your tank. (Don't the additives help remove the water?)

My car failed to start in the winter last year and the only explanation seemed to be gas line freeze up from the tank of gas I'd bought the last time I was running it. After being pushed into the garage and sitting there for a few days it started up again.

Demo24
01-25-2011, 09:06 AM
I think the danger is that you happen to get bad gas you can get water in your tank. (Don't the additives help remove the water?)

My car failed to start in the winter last year and the only explanation seemed to be gas line freeze up from the tank of gas I'd bought the last time I was running it. After being pushed into the garage and sitting there for a few days it started up again.

More likely the battery was cold and couldn't provide enough power for the starter to turn the engine over fast enough.

Vetterin
01-25-2011, 09:13 AM
I think the danger is that you happen to get bad gas you can get water in your tank. (Don't the additives help remove the water?)

My car failed to start in the winter last year and the only explanation seemed to be gas line freeze up from the tank of gas I'd bought the last time I was running it. After being pushed into the garage and sitting there for a few days it started up again.

HEET will definately absorb the water in gas but I don't think it's needed as much now as it was years ago due to the way the gas is now formulated.
Anyway, to answer your question - you would be better off using ethanol during the winter to help prevent gas line freeze.

desy
01-25-2011, 10:06 AM
Yep the winter formulations esp the ethanol blends have gas line antifreeze already in.
And yes its not the gas that freezes but water from either bad gas or driving around with less than half full tanks as condensation builds up.
The fuel filter will keep it out of your engine and gas line anti freeze bonds with water and allows it to pass through the system. The fuel filter is typically where the freezing happens as a concentration point.

yh125d
01-25-2011, 10:47 AM
huh, considering how much NG companies to keep their nat gas completely devoid of water, I'm surprised water in gasoline would ever be a concern.

LTC8K6
01-25-2011, 12:21 PM
huh, considering how much NG companies to keep their nat gas completely devoid of water, I'm surprised water in gasoline would ever be a concern.

Well, ethanol is hygroscopic...

It attracts and holds water...

yh125d
01-25-2011, 02:01 PM
Well, ethanol is hygroscopic...

It attracts and holds water...

Yeah, didn't think of that. Sugar and all. But even so, if it's stored properly (i.e., airtight, only exposure to air as when its pumped in the tank, which is minimal), seems like getting enough water in there would be extremely rare

Bignate603
01-25-2011, 02:20 PM
During winter it used to be relatively common to get condensation inside the gas tank which would collect until you had a decent amount of water inside your tank. You could lessen this effect by keeping your tank mostly full so sometimes you'll run into a person (usually an older person) that says you should keep your tank topped off during the winter. The water from the condensation could freeze up or just make the engine run like crap. Pure gasoline and pure water don't really mix so rather than getting a little bit of water mixed with gas sucked into your gas line you'd get a big gulp of pure water. If that got to your engine it could sputter and die, or if you turned off the car with it in the line it could freeze up.

You could dump in HEET or dry gas which was an alcohol which would mix with the water and get it into solution with the gas. With the water mixed evenly into the gas the engine never got fed a big slug of pure water so it could run ok and you never got a gulp of pure water sitting in your gas line which could freeze.

Gas with ethanol in it won't need drygas or the equivalent because it already has enough alcohol in it to get the same effect.

yh125d
01-25-2011, 02:25 PM
How would you get condensation inside a gas tank? They're mostly air tight, and are typically under slightly above atmospheric pressure with what vapor does leak out.

boomerang
01-25-2011, 02:28 PM
How would you get condensation inside a gas tank? They're mostly air tight, and are typically under slightly above atmospheric pressure with what vapor does leak out.
The moisture in the air in the tank will condense on the cold walls of the tank when atmospheric conditions support it.

Bignate603
01-25-2011, 02:36 PM
How would you get condensation inside a gas tank? They're mostly air tight, and are typically under slightly above atmospheric pressure with what vapor does leak out.

They're mostly sealed but there still is some air leakage. Because the water will tend to group up in pure gas rather than disperse it can take surprisingly little to cause an issue. Also, I've typically heard about the issue happening years ago on older cars with the gas that was available at the time (so no ethanol or additive to alleviate the issue). It's possible that 2 or 3 decades ago the fuel system wasn't as well sealed and made the problem worse.

zsdersw
01-25-2011, 02:48 PM
Heet is alcohol. Fuel with 10% ethanol should have a considerably lower freeze point than regular gasoline.

Based on a quick Google, gasoline has a freeze point of -40F. I don't know if that's for 10% ethanol blends or not. Ethanol has a freeze point of -173F.

Where do you live? Alaska?

Perhaps -40C, but not F.

Howard
01-25-2011, 02:58 PM
Perhaps -40C, but not F.
-40C and -40F are the same thing.

yh125d
01-25-2011, 03:05 PM
The moisture in the air in the tank will condense on the cold walls of the tank when atmospheric conditions support it.

I know how condensation works...


But neither the low amount of humidity in the air nor the temperature difference between the air and the walls of the tank seem enough for it to become a concern. I guess it just takes less than I'd have imagined

CraigRT
01-25-2011, 03:39 PM
Gas line antifreeze at least outside the arctic is an annoying marketing scam.

Poor suckers still buy it in climates that don't go that far below 0.

Totally unnecessary.

desy
01-25-2011, 03:39 PM
In winter condensation happens often think frost and a car is a volotile environemnt so lots of short trips heats up cools down and if the tank is low lots of wall space for condensation to occur. It also occurs in the tanks at the gas station which can be where a lot of water comes from.
Its one of the reasons to keep your tank half full all year but really with the new blends and ethanol it happens much more rarely than before.

zsdersw
01-25-2011, 03:55 PM
-40C and -40F are the same thing.

True, and it's the only point at which the scales meet. Gasoline doesn't freeze at that warm of a temperature, though.

Gas freezes at -180ºF or lower.

Jet fuel freezes closer to -40º

Meghan54
01-25-2011, 04:29 PM
huh, considering how much NG companies to keep their nat gas completely devoid of water, I'm surprised water in gasoline would ever be a concern.

Well, ethanol is hygroscopic...

It attracts and holds water...


We have this discussion almost once a week on the boating forums I frequent.

True, ethanol is hygroscopic, but is so slow in its absorption rate of water that a car being used regularly, like a tank of gas every week or so, will never have a problem with phase separation. The problems seem to crop up when a tank of gas is left to sit for extended periods.....like weeks and months. Then, there's time for the ethanol to attract moisture out of the air.

I'd be more worried about my gas station's tank condition and whether they're leaking gas out and water in.

Eli
01-25-2011, 09:06 PM
True, and it's the only point at which the scales meet. Gasoline doesn't freeze at that warm of a temperature, though.

Gas freezes at -180F or lower.

Jet fuel freezes closer to -40

Thinking about it, it does seem erroneous. I got the data from this: http://www.afdc.energy.gov/afdc/pdfs/fueltable.pdf

LTC8K6
01-25-2011, 09:18 PM
We have this discussion almost once a week on the boating forums I frequent.

True, ethanol is hygroscopic, but is so slow in its absorption rate of water that a car being used regularly, like a tank of gas every week or so, will never have a problem with phase separation. The problems seem to crop up when a tank of gas is left to sit for extended periods.....like weeks and months. Then, there's time for the ethanol to attract moisture out of the air.

I'd be more worried about my gas station's tank condition and whether they're leaking gas out and water in.

We'd be talking about liquid water in the system or the tank though, not water vapor. Water vapor condenses into liquid overnight in a tank with a lot of air space. If the air is humid, the condensation can be significant.

The problem comes up when storing or piping ethanol as well. In the low points of petroleum pipelines, water accumulates. Gasoline will float on this water and be pumped right past it with little problem. Ethanol will absorb the water and carry it into the supply.

All that said, my original opinion stands. With a quality fuel, there's no need to worry about water or freezing.