G100UL unleaded avgas approved

Joe Pilot said:
Distribution will be the problem
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What will FBO's do, add another tank ? Doubt it. So chicken and egg. Need some FBOs to bight the bullet and make the switch and that in effect makes the choice for anyone buying fuel from that FBO.
 
Joe Pilot said:
What will FBO's do, add another tank ? Doubt it. So chicken and egg. Need some FBOs to bight the bullet and make the switch and that in effect makes the choice for anyone buying fuel from that FBO.
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No need, they will just put the GAMI fuel in the 100LL tank since they can be mixed and over time the 100LL will eventually be diluted out. FBOs won't sell both. There wont be any knot tying.
 
Captain Sweet T said:
I have to imagine were still years away from this happening
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Nobody ever said this will happen right away. At least it isn't like some say about hydrogen fuel cells; 20 years away and always will be.
Joe Pilot said:
Distribution will be the problem
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Short term, and fairly easily solvable.
EdFred said:
No need, they will just put the GAMI fuel in the 100LL tank since they can be mixed and over time the 100LL will eventually be diluted out. FBOs won't sell both. There wont be any knot tying.
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Exactly.
 
The apparent fact that this new fuel can be mixed with 100LL in the same tanks and pumps is super encouraging and will make a rollout actually possible.
 
Missed my point. No, they won't add another tank and so when they switch to this fuel . . . so will you.
 
Racerx said:
The list is interestingly composed.
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I wonder what’s the newest engine in that new list. Seems mostly pretty old, with plenty of Wright, Pratt&Whitney. Were they originally intended for octanes below 100?
 
NoHeat said:
I wonder what’s the newest engine in that new list. Seems mostly pretty old, with plenty of Wright, Pratt&Whitney. Were they originally intended for octanes below 100?
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Prior to WWII, 87-90 octane avgas was common. A Beech 18, DC-3, or B-17 probably has a power setting sheet in the POH for at least one fuel with less than 100 octane.
 
Captain Sweet T said:
I have to imagine were still years away from this happening
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I don't think it will be that long... I expect GAMI 100UL deliveries will begin in certain California locations in the next few months... driven by early adopters (like flight schools) and local regulations outlawing leaded avgas. Beyond that, the logistics of rollout depend on how quickly the current blenders of unleaded avgas license GAMI technology, if they do...
 
Clip4 said:
Until the STCs are out, there are no approvals.
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There are already STCs issued for a limited number of airframes and engines... this recent engine list was a major expansion, adding 611 engines by make and model. In November, the FAA has promised a similar expansion of airframes that pair with these engines.
 
Racerx said:
The list is interestingly composed.
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The FAA's first traunch of approvals, in July, was for seven Cessna 172 models and their associated engines.
This second traunch was accelerated by the FAA due to keen interest in moving forward with unleaded avgas (I'm guessing that's regulatory action in California, with other locations interested in adding on.) These are 80 octane and 91 octane engines.
The third traunch includes the aircraft and engines that require 100LL today, which awaits the formalization of two final tests GAMI says... one of which is in progress, and the other which is slated to begin soon. GAMI says 2Q22 for fleet-wide approval.

Paul
 
Joe Pilot said:
when they switch to this fuel . . . so will you.
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I'm thinking that won't be driven by cost savings, as GAMI says the cost of manufacture is slightly higher. But, regulatory outlawing of lead, or unavailability of 100LL as blenders exit that business, or desire of communities or companies to move away from lead will drive that adoption.

Paul
 
I'm wondering why the STC route. Seems like a simpler way, and less open to cheating, would have been to charge the refiners a royalty, possibly time-limited rather than open ended.
 
DoubleD said:
I'm wondering why the STC route.
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FYI: It's a more efficient route. Since fuel type/grade is part of most airframe/engine type certifications it is cheaper and easier to use one (or several) AML-STC approvals vs revising every TC for every airframe/engine one would want to use the GAMI fuel in.
 
DoubleD said:
I'm wondering why the STC route. Seems like a simpler way, and less open to cheating, would have been to charge the refiners a royalty, possibly time-limited rather than open ended.
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They are doing both, but I suspect the number of aircraft owners who won’t pay for an STC for an FAA approved fuel will be substantial. I don’t see a reason why others can’t sell less expensive STC.
 
Clip4 said:
I don’t see a reason why others can’t sell less expensive STC.
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Given GAMI went the STC route vs the ASTM route I think you'll end up seeing "free" STCs by various providers to use the fuel. I don't think the AVGAS market was big enough to get a new ASTM rating which is the direction the JET A/turbine side is going and from what I've seen will require no additional approvals to use the new blends of turbine fuels.
 
So what happens when an FBO adds this to the 100LL tank and I have an O-540. Looks like we can’t use that airport anymore.
 
DesertNomad said:
So what happens when an FBO adds this to the 100LL tank and I have an O-540. Looks like we can’t use that airport anymore.
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You can certainly still use the airport, but receiving fuel services there may be at your own peril. :grin:
 
DesertNomad said:
So what happens when an FBO adds this to the 100LL tank and I have an O-540. Looks like we can’t use that airport anymore.
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My question is if/when more engines, like your O-540 and my IO-520 will be added to the approved list? Is it just a matter of testing, or is there some known reason keeping these engines off the list? If my home drome adopts G100UL, I wouldn't mind too much as long as it is temporary. I think the end result is worth a little inconvenience.
 
I believe I read that 100UL is significantly heavier per gallon than 100LL. As such, there could be airframe structural considerations requiring a case by case STC for each aircraft.

But I'm not holding my breath... 94UL has been out for a while now, but nobody seems to actually sell it. Me, I'd happily use mogas, but getting it without ethanol is impossible around here, so the few airports that once had it no longer do.
 
Dana said:
I believe I read that 100UL is significantly heavier per gallon than 100LL
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In an article I read in Cessna Flyer last night, it reported that 100LL is 5.87 lbs/gal., but the 100UL is 6.3 lbs/gal. So for 74 gallons in my 182, it's about a 32 lb. "penalty" -- or, to put it differently, I could carry 5 less gallons if I wanted to maintain the same fuel weigh. Smaller tanks would equal a smaller "penalty." The article also discussed the author's sense that the 100UL would burn cleaner, and reduce plug fouling, etc.
 
ldhilljr13 said:
In an article I read in Cessna Flyer last night, it reported that 100LL is 5.87 lbs/gal., but the 100UL is 6.3 lbs/gal. So for 74 gallons in my 182, it's about a 32 lb. "penalty" -- or, to put it differently, I could carry 5 less gallons if I wanted to maintain the same fuel weigh. Smaller tanks would equal a smaller "penalty." The article also discussed the author's sense that the 100UL would burn cleaner, and reduce plug fouling, etc.
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Hmmm. I'm wondering if for that extra mass the ul fuel has more btus per gallon?
 
ldhilljr13 said:
In an article I read in Cessna Flyer last night, it reported that 100LL is 5.87 lbs/gal., but the 100UL is 6.3 lbs/gal. So for 74 gallons in my 182, it's about a 32 lb. "penalty" -- or, to put it differently, I could carry 5 less gallons if I wanted to maintain the same fuel weigh. Smaller tanks would equal a smaller "penalty." The article also discussed the author's sense that the 100UL would burn cleaner, and reduce plug fouling, etc.
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Hmmm. I'm wondering if for that extra mass the ul fuel has more btus per gallon?
 
PaulMillner said:
The FAA's first traunch of approvals, in July, was for seven Cessna 172 models and their associated engines.
This second traunch was accelerated by the FAA due to keen interest in moving forward with unleaded avgas (I'm guessing that's regulatory action in California, with other locations interested in adding on.) These are 80 octane and 91 octane engines.
The third traunch includes the aircraft and engines that require 100LL today, which awaits the formalization of two final tests GAMI says... one of which is in progress, and the other which is slated to begin soon. GAMI says 2Q22 for fleet-wide approval.

Paul
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Except my 0-360 a3a that would run on 91 octane is absent. Kind of a bummer we get rid of lead and end up heavier.
 
ldhilljr13 said:
In an article I read in Cessna Flyer last night, it reported that 100LL is 5.87 lbs/gal., but the 100UL is 6.3 lbs/gal. So for 74 gallons in my 182, it's about a 32 lb. "penalty" -- or, to put it differently, I could carry 5 less gallons if I wanted to maintain the same fuel weigh. Smaller tanks would equal a smaller "penalty." The article also discussed the author's sense that the 100UL would burn cleaner, and reduce plug fouling, etc.
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We always flight planned avgas at 6 lbs per gallon.

Data says 100UL is 6.25 lbs per gallon.

I am more concerned about the pricing :)
 
Dana said:
100UL is significantly heavier per gallon than 100LL.
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It's 5% heavier.

there could be airframe structural considerations requiring a case by case STC for each aircraft.
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In the initial STC (for the Lycoming powered 172s), the FAA approved of handling this merely by adding a page to the POH that instructs the pilot to do the W&B using the higher weight, if any 100UL is on board... or, to calculate the actual weight by percentage of 100LL and 100UL on board. The FAA does not seem to be concerned that 5% greater fuel weight poses structural considerations.

Paul
 
Doug Reid said:
I am more concerned about the pricing
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I think many of us are, both for the 100UL per gallon, as well as for the STC. FWIW, the Cessna Flyer article said that 100UL might be $0.60-0.85/gallon higher, so not an insignificant jump (query whether the benefits of the cleaner fuel reduce some engine maintenance costs to offset the higher per-gallon fuel price). As for the STC, the article speculated that it might be linked to the HP of the engine involved (e.g., X dollars per engine horsepower).
 
ldhilljr13 said:
I think many of us are, both for the 100UL per gallon, as well as for the STC. FWIW, the Cessna Flyer article said that 100UL might be $0.60-0.85/gallon higher, so not an insignificant jump (query whether the benefits of the cleaner fuel reduce some engine maintenance costs to offset the higher per-gallon fuel price). As for the STC, the article speculated that it might be linked to the HP of the engine involved (e.g., X dollars per engine horsepower).
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Tim Roehl was on the piper forum and said this about the STC cost ...

"Like other alternative fuels STCs (i.e. mogas) that have been around for some time, we anticipate the cost of the STCs to be based upon HP and in the same range, i.e. $200-$400 for most single engine aircraft."
 
Andy Appeltans said:
https://www.aopa.org/news-and-media...s-hundreds-more-engines-to-use-unleaded-avgas

A lot more engine are approved.
Now waiting for the airframes those engines are in.
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As you said here, the article states that a list of approved airframes will be forthcoming, but why is that even important? What difference does it make what airframe an engine is in as long as that engine is approved for the new UL fuel? Maybe I'm missing something here, but if a particular engine can legally use a particular fuel, it shouldn't matter one bit what airframe it is installed in.
 
Kevin Eggert said:
As you said here, the article states that a list of approved airframes will be forthcoming, but why is that even important? What difference does it make what airframe an engine is in as long as that engine is approved for the new UL fuel? Maybe I'm missing something here, but if a particular engine can legally use a particular fuel, it shouldn't matter one bit what airframe it is installed in.
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Might be tanks, tubing and other fuel system parts tied to the airframe. That's why Mogas with ethanol is often an issue.
 
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