Topping off the fuel & winterizing it, what grade of gas do you use?

[WayneG]

Getting the MH ready for winter storage here in the Northeast.
I just added Sta-bil and brought the tank up to about 3/4 full. (I will top it off later)
This year I have been using gas of 90 octane or better. Today Sunoco 93 octane.

My 454 has the TBI fuel injection modification and the engine is a replacement from about 60K miles ago.

I cant say definitively that I am getting better MPG with hightest, but it does seem to run better and have a bit more hill power on it.

I hear it is also better for storage over the winter.

What is your experience with hightest vs lower grade fuel?

[dznf0g]

Premium does have a longer storage life than regular. I would store with premium AND Sta-Bil. Tank should be full for storage.

[WayneG]

I do plan on filling it to the top next month, I may do one more run in November and I like to minimize weight over the mountains.

[bobmiller1]

Wayne, I only use premium from Stewart's......it's ethanol free, and it's great for the chain saws, lawn mowers, etc. Regards, Bob

[jcl]

I would pay far more attention to whether it was ethanol free than to the octane rating.

[jcl]

Originally Posted by dznf0g

Premium does have a longer storage life than regular.

Why? If the concern is reduction in AKI over time, then premium does have a head start (if it drops four points, that may matter less to a specific engine). However, I don't see why it would be more stable, more resistant to phase separation, etc. Some premium doesn't have ethanol, which makes it better for long term storage, but that is a different issue.

[perryg114]

Ethanol absorbs water and promotes corrosion and also attacks rubber. Use ethanol free of whatever grade you can find it in. Octane is a secondary consideration. Fill the tank all the way up to reduce condensation. The less air space the less water will condense out.

Perry

[dznf0g]

Originally Posted by jcl

Why? If the concern is reduction in AKI over time, then premium does have a head start (if it drops four points, that may matter less to a specific engine). However, I don't see why it would be more stable, more resistant to phase separation, etc. Some premium doesn't have ethanol, which makes it better for long term storage, but that is a different issue.

Don't know why, but read it somewhere.

[supercubep]

I use 100 octane low lead aviation fuel in my generator ,ATV , UTV, Chain saw, mowers etc.. It doesn't go bad, it has a trace of lead, the purity is guaranteed, and the engines love it. 100 octane aviation gasoline has a dye in it guaranteeing its quality and octane value. I also run it in my 1930 Model A and my 1955 1 ton Ford flatbed dually. Obviously you can't run this type of gasoline in modern gas vehicles because of current emissions standards, but for older vehicles and small engines it's great. Aviation is not cheap, about $5.80 a gallon in Idaho. Prices vary in different states. You can get the fuel by going to your local airport with gas cans and the local operator will fill them for you.

[dznf0g]

Originally Posted by supercubep

I use 100 octane low lead aviation fuel in my generator ,ATV , UTV, Chain saw, mowers etc.. It doesn't go bad, it has a trace of lead, the purity is guaranteed, and the engines love it. 100 octane aviation gasoline has a dye in it guaranteeing its quality and octane value. I also run it in my 1930 Model A and my 1955 1 ton Ford flatbed dually. Obviously you can't run this type of gasoline in modern gas vehicles because of current emissions standards, but for older vehicles and small engines it's great. Aviation is not cheap, about $5.80 a gallon in Idaho. Prices vary in different states. You can get the fuel by going to your local airport with gas cans and the local operator will fill them for you.

All fuel eventually goes bad. The fuel you describe, I believe, ha s 2 year shelf life. Premium is 1 year. Regular is 6 months. This varies in different readings, but is my yardstick.

[Bob662]

I also have access to 100LL, and small engines do love it. It's also more stable that auto gas. But engines also love non-ethanol regular. Were it me, I'd fill with non-ethanol of whatever grade you can get (I've never seen it available in anything but regular/87 octane), and add some Sta-Bil or an equivalent fuel stabilizer if it's going to sit for months.

I believe the condensation thing is vastly overstated. I've heard that forever about aircraft fuel tanks. My experience from the past 50 years of aircraft ownership is water in the tank comes from being outside and rain or dew penetrates the fuel cap gaskets. I've never gotten a drop of water from sumping airplanes that were stored inside and weren't exposed to precipitation.

[supercubep]

Aviation gasoline has a life time more than 3 years, there are some cases of 5 to 8 years with engine startup with uncontaminated fuel. Back to the point, it's easy, no mixing, and reasonably priced. Not the crap they they sell at gas stations today. Just saying.🙂

[MelGoddard]

Originally Posted by jcl

I would pay far more attention to whether it was ethanol free than to the octane rating.

Absolutely!

[MelGoddard]

Originally Posted by supercubep

Aviation gasoline has a life time more than 3 years, there are some cases of 5 to 8 years with engine startup with uncontaminated fuel. Back to the point, it's easy, no mixing, and reasonably priced. Not the crap they they sell at gas stations today. Just saying.🙂

DO NOT USE AVGAS!
It had tetra-ethyl lead in it, as well as other compounds that could cause corrosion in your engine during long term storage.
Aero engines are designed for Avgas; auto engines are not!😬

[MelGoddard]

Originally Posted by perryg114

Ethanol absorbs water and promotes corrosion and also attacks rubber. Use ethanol free of whatever grade you can find it in. Octane is a secondary consideration. Fill the tank all the way up to reduce condensation. The less air space the less water will condense out.

Perry

Exactly!

[supercubep]

Aviation gasoline: Sorry to say I dispute that. Yes it does have lead. I have never with the exception of lead, and its effect on modern emissions systems , have heard of issues with non aircraft engines. I have run it for years on multiple types of vehicles including boats with out an issue. I've been in aviation for over 46 years and that's a new one to me.
And never any internal corrosion found in any vehicles including my aircraft.

[WayneG]

I have a county airport about 1/2 from my home, they show 100LL at $5.00 a gallon. Just how much lead is LL compared to the old leaded regular? I assume environmentally, it is not the best?

[Moflash]

Premium unleaded without ethanol and Seafoam fuel treatment.

[supercubep]

I can't tell you exactly what the lead difference is between leaded regular and LL 100 avgas. I'm sure the lead content is a lot less in today's aviation fuel. As far as I know, no other gasolines have lead anymore. The production of 100LL is miniscule nowadays compared to automotive gasolines.

[MelGoddard]

Originally Posted by supercubep

I can't tell you exactly what the lead difference is between leaded regular and LL 100 avgas. I'm sure the lead content is a lot less in today's aviation fuel. As far as I know, no other gasolines have lead anymore. The production of 100LL is miniscule nowadays compared to automotive gasolines.

The lead content was there of course, to control detonation, and improve the flame front. A side benefit was a ight coating on the valves, (exhaust esp.) to prevent valve recession into the seat.
There are other compounds in Avgas, of course, to control the Reid Vapour Pressure and so forth.
Being retired for a few years, I don't have my "AC43-13-1,2,3 etc. to refer to for specs, and my Esso product books have long gone too.
But I 'll bet that if you researched some of the products, you could get a fine understanding of Aviation fuels and products.
I did; but that was then, and this is now.