How to store fuel long term?

[Naphtali]

1997 LX450, 73.8K.

I tend to drive sporadically -- that is, I'll drive tanksful of fuel, then the truck will sit for months.

I'm concerned about cracked fuel decomposing/reverting to something extremely inefficient or, perhaps, harmful.

I have a friend who owns several piston aircraft who stores his vehicles about seven months each year. He runs them until fuel tanks are nearly dry, then fills tanks with AVGAS. He tells me it is DISTILLED rather than CRACKED and will be unaffected by long-term storage. I have no clue what he is talking about.

One of his businesses is in Alaska. He tells me that Alaska gasoline is routinely distilled rather than cracked. So he has zero maintenance problems pertaining to fuel for vehicles he stores there.

What procedure/additives/other do I want to use to keep my truck trouble free when running fuel that has been sitting for as much as a year? I just added a concern. I keep 25 gallons of fuel at my cabin.

 

[tarbe]

Cat-cracked gas has olefins in it, distilled gas does not.

The olefins are more reactive due to the ( C=C ) double bond and form gums and varnish.

 

[RavenTai]

Cat-cracked gas has olefins in it, distilled gas does not.

The olefins are more reactive due to the ( C=C ) double bond and form gums and varnish.

I wish I knew more about chemistry, is that the more scientific way of saying that short hydrocarbon chains are bonding on thier own forming longer hydrocarbon chains?

The most common AvGas is 100LL, it has some lead in it, I do not know specifically about lead but in general heavy metals in the exhaust stream do not get along with Cat and O2's,

I use sta-bil in my lawn equipment as the gas usually sits around for months in the can and sometimes longer in the tank, seams to work, you might want to look into its use in automotive engines.

 

[tarbe]

Has nothing to do with the length of the chains. The double bond (in the olefin) has an extra electron available to get in trouble with oxygen and other available elements.

 

[esde]

I use stabil as well, and have had no problems. Motorcycle riders use stabil also, as they tend to be seasonal. SD

 

[IdahoDoug]

'Stabil' brand fuel stabilizer. Having said that, modern fuels are much more stable than the old days and a few months or a year would not concern me. I'd want full tanks.

I left an old car unprepped for 7 years about a decade ago. Arrived in the barn with starter fluid and a new battery and within minutes the 25 year old V8 was idling smoothly with no issues whatsoever. I'd think modern fuel injection (80, for instance) would be even more robust in this situation. Much ado about nothing.

DougM

 

[yosemitesamiam]

'Stabil' brand fuel stabilizer. Having said that, modern fuels are much more stable than the old days and a few months or a year would not concern me. I'd want full tanks.

I left an old car unprepped for 7 years about a decade ago. Arrived in the barn with starter fluid and a new battery and within minutes the 25 year old V8 was idling smoothly with no issues whatsoever. I'd think modern fuel injection (80, for instance) would be even more robust in this situation. Much ado about nothing.

DougM

I tend to think to opposite, as a modern fuel system has much higher tolerances and less margin for error than older cars.

 

[Proven]

Fuel storage has everything to do with where you live, how hot it is getting, and whether the engine has carb's or injectors. On the 80's, if you were going to not run the truck for 6 months I probably wouldn't be too worried about it, but if you were I would suggest that you run a fuel conditioner/stabilizer in it.

The largest concern with fuel storage from what I know is octane levels diminishing over time, varnish building up (usually requires air to dry the fuel),or humidity being absorbed into the fuel. With the new ethanol blends this humidity problem is expounded. In a car though, particularly an 80 series LC with fuel injection, there is very few avenues for this to happen. Your worst fear would be octane levels.

I could recommend some products I use for outboard engine storage and maintenance:

Yamaha Ring Free: This is a product that was designed for Yamaha by Oronite (Chevron's additive company) which is based on the Techron molecule. The bottle is nearly 100% Techron which devarnishes, disperses varnish, and debonds carbon when combusted. I am using some now to clean up my EGR.

Fuel Conditioner/stabilizer: I use this is the same tank with the Ringfree. This ensures that the octane levels are maintained and that the fuel does not "Gum" or build up varnish due to oxidation. Makes it play nice with metals also.


Though, personally....I think that you'd be fine as is with a full tank of FRESH gasoline in that tank.

 

[IdahoDoug]

Sam,

Unlike older fuel systems, systems on lawn mowers, snow blowers, outboards, and older cars, a fuel injection system is a closed system to air. Without air, the fuel remains very stable.

I casually leave whatever fuel's in the boat when I park it in October in there until I start it in May. Seven months every year for the last decade. Never a problem. Full tanks are best of course, but I'm trying to convey that I think this is much ado about nothing. Modern fuels are more stable than ever. I would have no problem driving a car and parking it for 6 months at a time and the car wouldn't have any problems either. The presence of a problem is unsupported with facts or real world experience here, while the absence of a problem is supported.

DougM

 

[yosemitesamiam]

Hey Doug...I do see your point as it makes good sense...and since it is based on actual observation, I guess I can't disagree. Everytime I've left my lawnmower parked for more than a couple months, the gas tank ended up dry and I had to fill it anyway! LOL

 

[mnwolftrack]

Seafoam is a great fuel additive. I've used it for years on outboards and ATV's, but it's also just as good for automobiles. Not only does it help stabilize the fuel, it also helps clean the fuel system. It can be used in three ways--in the gas, in the crank case, and sucked in through a vacuum line on the intake. It's very popular with the Land Rover crowd (I've owned two Discovery's) due to the fact the rovers are notorious with sticky valves. Seafoam helps clean up the valve system. There's some previous posts regarding seafoam on this board too, though Toyota's do not have the problems Rovers do. It has something to do with the U.S. fuel quality, becuase Rover's in Britian, Australia, etc.... do not have sticky valve issues. Seafoam is available at many auto parts stores including Checker Auto Parts and Napa.