I have access to a couple of sealed barrels, marked expiration of May 2021. To get any fresher fuel requires shipping barrels to the middle of the Pacific. Everything I've read suggests that this shouldn't be an issue; it lasts for many years when sealed. I used AVGAS in Resolute Bay that was 1 year nominally expired, with no issues. I'd be interested in the experience and views of those on here, as to whether my intention to use it is a good idea or not.
Fuel keeps your airplane in the air. In todays age of liability, I doubt you will find anybody who is willing to say it is okay to use expired fuel, regardless of what they think. I used to fly out in the middle of the Pacific too, and all Avgas came in 55 gallon drums. We used it up so fast that we never had any expired barrels to tempt us.
No, the FAA does not advise stocking up on 100LL now and selling it in the gray market when it is phased out
I've seen gas pulled from airplanes that sat for decades. Plane restored, tanks filled with the "expired" gas. No issues, but I'm just some guy on the Internet
2 X 55 gallons does not seem to be enough fuel for your usual Pacific legs. Obviously if you need more barrels than that, the choice to purchase all fresh is obvious. No specific knowledge, but if you have a routing that requires only the 110 gallons, there could be some mixing of your existing tankage to mitigate any staleness, and besides, your power output is less the 75% to maximize range anyway except on initial climb.
The rule of thumb is 2 years on properly sealed avgas barrels. There are international guidance docs on this with several good ones from Canada TCCA. Main issue with avgas is it loses "volatility" over time.
I’ve flown 10+ year old avgas w no issues. A friend dug up a refinery and found a few hundred gallons in pipes that tested good. IIRC the first thing that happens is the Reid Vapor Pressure drops off. This is something that can be tested. btw The guy that did the testing also ran a refinery in Kentucky (?).
Many years ago, I bought a 172 that had been sitting in a hangar untouched for 14 years. The owner topped it off when he put it away, and when I got it the fuel level had dropped to 3/4 (evaporation?) The engine started normally, and ran fine on the ground using the old fuel, so I topped it of with fresh 100LL and went flying (after getting the annual done). Burning it was A LOT easier than finding a way to dispose of it.
Based on feedback here, and also chatting to the manager of aviation fuel quality at one of the oil majors, I am feeling comfortable with using the old fuel. Thanks all.
I also feel it is still good, especially if it starts normally. The light ends evaporate first which will cause hard starting. I sell race gas at work. Race gas has stabilizers in it when made and will last for years when properly stored. I think aviation gas is similar. The car in my hangar has some 2018 and some 2021 100LL in it. I start it 3-4 times a year. It starts every time once it gets gas up to the carburetor. A few cranks and lot's gas petal pumping. Remember those days? This same car was stored in my home garage from 1986 to 2003 with straight 110 octane leaded race gas in it. I started it 2-3 times a year and replaced battery's and kept the fuel tank topped off.
I wouldn’t hesitate to burn 5 or even 10 year old avgas from sealed drums. I burn 10 year old car gas in plastic barrels every time I’m at my cabin. As I walk my neighborhood most of us have 500 gallon fuel tanks for avgas and with the price of fuel most of us don’t fly as much as we used to. I have no doubt there are tanks (vented) with 3-4 year old fuel and guys are burning it without problems. For all the years I stored my airplanes outdoors in winter I never thought twice about firing up in spring and flying away on last year’s fuel.
