Old Gas

[Fortecarbon]

I am sure this has been covered before and I did some searching but lots of opinions and little science.

I am quite familiar (I am sure most BTOG regulars are) with the general problems associated with old gas - evaporation of additives, Ethanol/water separation, particulates, varnish, etc.

What I am really after is... what is left after old fuel has been filtered and free of water? I know it still burns. In fact, I think it has more volatile characteristics when tossing small amounts on a bonfire. Could that be due to the lack of octane?

If you are interested in the reason I am asking... I finally sold my old boat last spring, but before I did, I pumped the 30 gal or so of fuel that was in the tank into a portable tank (with wheels kind-of thing). Now I have to figure out how to get rid of this 4 + yr old gas.

My plan is to filter the gas, add some octane booster, mix with 50/50 fresh 93 octane gas, and run it in my old Chevy blazer plow truck (with a marine 350 and an Edelbrock carb). The Blazer also has a marine spin on fuel filter in the engine bay - I think 10 micron. The Blazer does not come out of low range and rarely sees over 1500 RPM, although it will see some torque loads if plowing.

At $4.29 / gal for premium in the great state of Connecticut, I would like to reduce the fresh fuel ratio even further, but not sure if that is a good idea.

Thanks for all your help!
clint

 

[Quest]

Old gas lost most of it's volatile "aromatic" part of the gasoline (aka "essence" ) and whatever remains are primarily varnish ---things that don't burn or just barely burn but leaves a lot of carboneasous soot.

Since the decomposition of gaoline will eventually turn into varnish-like stuff(and gas goes rancid), it's a one-way (directional-wise) affair and no known means to reverse the process.

I know no additives out there (including the ever-so-famous, aggressively worded PRx-G product) that can reverse this process.

Sorry but the proper way is to find a facility to dispose of these old gasoline safely and in an environmentally-sensible manner.

Q.

p.s. I won't even risk ruining my car (injectors, carbons inside my combustion chambers, killing my O2 sensors, etc.) by mixing it with fresh gas + whatever have you additives and try to get something out of it.

 

[Phishin]

I have 35 gallons of old (from March 2013) pre-mix 2-stroke gasoline from my boat. This gas has been stored in 6 gallon plastic cans and stored inside a covered boat all summer.

I'm just gonna funnel this gas into my truck. Shouldn't hurt a thing. But I'd never put it in anything I really was dependent upon, or any vehicle that's too nice.

 

[expat]

About two weeks back we were tidying things for the Fall and the wife asked what to do with the left over, (from the summer)ride on lawnmower gas. I told her to pour it into my Truck (a Carbed Toyota 22R) after she did that, she remarked how bad that gas smelled.
It turned out 'that Gas' was what I had drained out of an old Outboard motor tank (2 stroke) about 6 years ago!
The smell was overpoweringly sickly.
The old gas added to the truck accounted for about 60% of what was in the trucks tank. But the truck started and ran perfectly fine.
It was about three days before I got around the Fulling the truck with fresh gas, but I had no problems in the meantime running the old stuff.

BTW, there is no cat on the truck.

 

[nitehawk55]

I was going to say , carb with no CAT mixed with some fresh should be OK unless it smells like paint !

 

[Donald]

Mix it with used motor oil and return it to Walmart as used motor oil.

 

[wag123]

You guys can do what you want with that old/bad gas. After being in the business for as long as I have, and fixing many thousands of engines that have suffered problems from it, I would NEVER use any of it in ANY machine that I own, and I have access to hundreds of gallons of the worthless stuff every year.
If you use it in your car/truck you might get lucky and not have a problem with it. But, you might gum-up your fuel injectors, stick your intake valves open (and on an interference engine, destroy the engine), ruin your fuel pump and/or a couple of O2 sensors, etc, etc! Is it worth the risk? Not in my car it isn't!
What do you get when you mix 5 gallons of old/bad gas with 5 gallons of new/fresh gas?
10 gallons of BAD gas!

 

[fdcg27]

Thirty gallons of fuel is like a light snack to an old carbed SBC truck.
I'd run maybe a couple of gallons at a time in a full tank of fresh gas.
You'll certainly go through all of it over the course of the winter at that rate.
A little at a time shouldn't cause any harm at all.