I'm prepping my lawn equipment for the winter here in the Northeast, and I got to thinking about whether to drain the gas out of my mower, power washer, etc. or just use Sta-Bil. This also made me wonder if gasoline freezing would ever be a problem. I suppose I operate my car in subzero conditions sometimes without a problem, but my vehicle doesn't just sit for months on end. So the question is, at what temperature will gasoline freeze? Any chemists out there?

Also, do you have an opinion as to draining vs. stabilizing your fuel?

 

Diesel as far as I know freezes at -10 Celsius when not treated. Gasoline is much lower...I think 40-50 degrees Celsius so I think your fine

 

I'm sure Google can help you with the freezing point information but as far as how to store your power equipment, I drain the gas from the equipment and stabilize the fuel in my gas cans. Actually, since I don't use my stuff that often, I always stabilize the fuel in the gas can as soon as I fill it up. This way, the gas is always stabilized no matter if it's left over in the equipment or left over in the can.

Remember that if you drain the gas from the equipment, you should also drain the carburetor bowl to be sure you get everything out...

 

google.com/search?q=Freezing+point+of+gasoline

 

is it possible it is 2010 and there is someone using a computer that is not yet familiar with google, or bing, or yahoo?


Fuels like gasoline are really a cocktail of hydrocarbons. Thicker, oil-like stuff at room temperature with some thinner ones, and also aromatics that are gaseous at room temperature. So by freezing, you mean, when does it turn solid? The heavier hydrocarbons will start to solidify sooner than the aromatics.

The flash point of gasoline is about -97F, meaning that it will still burn at 97 degrees below zero. Most labs won't even have the ability to chill a sample down that far to find out! Even the -97F mark is going to vary, based on the additives in the sample.

Of course, if there is any water mixed in with the fuel, it can still freeze at around 32F, but that may depend on if there are any alcohols mixed with the sample. Methyl alcohol is a common additive you can buy to help keep water in your gas tank from freezing at low temperatures.

The thicker, heavier hydrocarbons, like paraffin will become solid at atmospheric temperatures. Some of the aromatics won't turn solid until -200F to -300F. Not something you'll see outside of a lab.

For more information, the American Society for Tests and Measurements (ASTM) has written a whole bunch of methods for testing, well . . . everything really, but list some methods that may be relevant: Methods D1015, and D1016 talk about freezing points of refined hydrocarbons. For $12 each, you can buy the method from ASTM.

Diesel and Jet Fuel are a different story- and there is no precise answer for your question. If you are storing your car throw some drygas in the tank with the fuel which will prevent any water in the fuel from freezing, but if you live in a state that requires 10-15% ethonol in the fuel, you may not even need drygas.

 

its not that gas freezes, its that gas goes bad when it sits for a while and can gum things up.

you're way better off to drain and run the equipment till it dies.
i used stabil once in a snowmobile, and still ended up having to drain the fuel cause it ran like crap.

 

This kinda confirms what I was thinking too. Thanks for everyone's input!