Fuel in tank for cars not driven much

To add my two cents: On cars that will take leaded, and on small engines, (chainsaws, etc., I use avation fuel. It has a little lead in in (not much), is at least 100 octane, and is cleaner and without ethanol. It costs about $5.50/ gallon, but the small engines don't use much, and if I am going on a trip, I will fill up with regulag gas station fuel. If the car is going into storage, I refill with avgas. So, the E-Type and the Packard are taken care of. I use "seafoam" marine fuel treatment in a full tank on the XK-8 when it goes in for it's long winter nap.

The whole ethanol thing is debateable - some folks don't think it makes sense to use your food as a motor fuel, but it does reduce the already ridiculously low pollutants to an even lower level.

Well, after taking the car out to Cars & Coffee this weekend I hunted down one of the few gas stations that sold Non-Ethanol fuel, paid and arm and a leg for it, filled up the tank and added seafoam. I will keep the tank topped off and treated from hear on out.

Unfortunatly I could not locate a station that sold 100 + octane in our area.

Blake must be spinning in circles by now. Phil, most pilots fill up if they aren't sure when they might fly again, then preflight check include checking the fuel by draining a little via the check valves. The fact is, regardles of the fuel quality, the tank areas that are open to atmosphere is where the corrosion starts, not where the fuel is, thus filling up is required for that reason.

Years ago I was inspecting a car for sale and the owner had a fleet of very expensive sports cars that were rarely driven. I asked what he did to the fuel during long periods under-cover, and he said he drives the car to near empty, then drives to the next door neighbor who has a private runway (wealthy area), and puts in a few gallons of aviation gas. After a short drive and the av-gas is through the system, he parks it. He said that av-gas is made to evaporate cleanly, with no residue. It made sense, some small planes sit for long periods and a sticky carb at a few thousand feet might be trouble.

Or, it could be modern folklore.

Phil.

In my son's motorcycle magazine I recently noticed an advertisement offering some sort of strip to be placed in the fuel tanks of bikes being stored. It indicated that the strip would progressively change colors as it absorbed moisture. it was to be replaced when it reached a certain color, I don't recall which color. Has anyone had any experience with these devices?

This is the same problem all boat owners have, so following their advice will work for your car (or chainsaw, lawnmower, weed eater, leaf blower, pressure washer, etc.)

If you do not use your gasoline engine often enough, then use non-ethanol fuel to prevent phase out of the ethanol when it is combined with moist air (which produces a layer of water-ethanol at the bottom of the sump which gets sucked up first). Do an internet search for gas stations in your area to find the ones that sell non-ethanol. There are several websites. Or check at your local marina. Adding Sta-Bil will also help preserve the fuel. Try to use hi-octane in your high compression E-type to prevent ignition problems. Keeping the tank topped up will lessen the surface area of exposed metal fuel tank inside where water condenses as temperature changes cause the vapors above the liquid fuel to expand and contract, thus introducing moisture laden air.

It is also good advice to use a dehumidifier in your garage to prevent moisture condensation (such as in the air or weeping under garage walls & floors) not only in your fuel tank, but also the hidden inside panels of your car where rust will start, and in your dash gauges and lamps where water causes corrosion and clouding. And drier air will reduce the chance of a film of grey mold growing all over the interior of your car. Here along the coast of South Carolina, dealing with moisture is a constant problem.

By now you should have already replaced your rubber fuel hoses and the floats in your carbs to ethanol-tolerant ones to prevent leaks.

Good luck!

I have to agree with the racing fuel. Just by accident I left racing hi octane fuel in a tank of a car buried in my garage about 10 years ago and just forgot about starting it up or driving it around. Left it for a year. I know bad. Had all those bad thoughts running through my head.
Opened up the tank and did not get that old fuel smell. Hit the key and of course the cork gaskets started leaking fuel all over the place. Let it sit for a half day and tried again. No leaks and started right up. It was an old engine that needed rebuild so I continued the test.(actually just couldn't get it out of the garage) Two more years on 105 octane. Same fuel. No problem. No compression drop. Runs like it always has. So, I donÔÇÖt recommend leaving the fuel in a car for over a year but I do try to find 104+ octane if it is going to sit.

Fuel goes bad because the lighter particles evaporate when exposed to air. The only way to minimize this evaporation is to reduce/eliminate the exposure. I do this by keeping the tank full up to just above the filler tube. I then tape over the breather hole. A partially filled tank has very large fuel exposure surface, the one filled up to the tube has a very small one!! Also, any partially filled tank will build up corrosion on the exposed areas. BUT, do not fill the tank to the very top of the tubes, as there must be space for the gas to expand in hot climates. If the car is to be left for long periods than after filling as above, disconnect the fuel pump feed and start the engine and let it run out of fuel.

Blake; I have 3 old cars that I drive from time to time, usually once a month at the least and durning the summer more frequently.
I use regular gas not ethanol and do not use 'Stabil' or other additive. When I drive them I put on 30 to 40 miles, mostly highway. I have never had any problem with 'old' gas. Been driving the TC since 85, the MGB since 07 and the Mustang since 04. Not necessarily a recommendation but what has worked for me. Joel.

Blake; I have 3 old cars that I drive from time to time, usually once a month at the least and durning the summer more frequently.
I use regular gas not ethanol and do not use 'Stabil' or other additive. When I drive them I put on 30 to 40 miles, mostly highway. I have never had any problem with 'old' gas. Been driving the TC since 85, the MGB since 07 and the Mustang since 04. Not necessarily a recommendation but what has worked for me. Joel.

Sunoco sells 100 octane (with 10% ethanol) you can pump directly into your car and 110 octane (sans ethanol) you have to purchase in separate containers. "Not legal in street cars"
Not all their stations have it though.

WWJLD?

What would Jay Leno do???? Jay has hundreds of cars so I thought I would check out his website. Found an interesting article. He actually mentions dropping a valve in one of his old Jags, due to old fuel drying out and causing a valve to stick.

Ckick the red text below that says "Made in America - All about Fuel" to see the video.

WWJLD?

What would Jay Leno do???? Jay has hundreds of cars so I thought I would check out his website. Found an interesting article. He actually mentions dropping a valve in one of his old Jags, due to old fuel drying out and causing a valve to stick.

The issues you cite are the reasons why I pump the fuel (with Stabil) out periodically and use it elsewhere. Actually, my pump doesn't reach the bottom of the tank so I'm more motivated to mix the old remaining gas with the fresher gas (adding a few more ounces of Stabil). The better solution is to drive them more often!

Regards,

I have been told to keep the tank full with stabil but would like to know what others think also.

I just feel that if you leave a full tank of gas in the car that might take up to a year to use then that gas will also cause other issued in the fuel delivery system and gum up your carbs as well?

Good Q, Blake. Here's what I did last year when I put about 500 miles on 1 of my OTSs...
1. I kept the tank full - to prevent rust inside the tank.
2. I added Stabil - to preserve the gas.
3. After several months I siphoned the gas out and into 1 of the other Jags - to be sure it didn't go to waste.
4. Repeat the above. (No known problems so far.)

I'll be interested to see what others say.
Regards,