Al

What is the evidence you have at hand G100UL does not work w all engines as the approved STC says?

My engine, a factory Reman TSIO520UB, took me safely from CA to NY and back and many other trips regularly, LOP, 70%+ power, high teens, you name it. That is my sample of one evidence, no other unleaded fuel in the market offers such for this type of engine.

I missed to say I mixed w 100LL in many different proportions without any consideration from my side.

If you read what this vendor or others say, timing changes, compression changes, fuel flow changes may be needed to burn those fuels. As someone said earlier , a distraction…

It is pure speculation, yes. Instead of "flaw," you could also call it "tradeoff." There is some tradeoff that the much larger companies were unwilling to make, which results in their fuel not working for all engines. It's highly unlikely that they didn't know how to make a fuel that, just like GAMIs, works for all engines. They've intentionally not done that.

The obvious question is...why? I'd love to get an answer to that.

Welcome Dan.

in the fuel formulations you're working with, do any of the constituents have substantially differing evaporation profiles?

What do you know about aromatic amines?

My answer was incorrect, timing changes will also be a major change requiring a form 337.

Thanks Larry,

The distillation profile for UL100E is similar to 100LL. It has slightly higher IBP and FBP and lower T10 but the rest of the points are within D910 specs. The distillation range is broader than 100LL by about 18 degrees C.

Aromatic amines are effective octane boosters but have some undesirable properties for gasoline including reactivity, high boiling points, and high polarity. This manifests itself as slow evaporation/vaporization, discoloration, a tendency to form gums and lacquers in oil pans and to swell and/or attack materials including certain types of paints, sealants, and elastomers.

Dan

Dan,

Thank you for being here. I can see your expertise in fuel chemistry.

Which on of your commercially available fuels
Most closely fits the profile of your aviation fuel?

Asked another way, would VP 110 have any undesirable
Characteristics if placed in a plane?

Dan I appreciate your participation here and I assume you're here to learn as well as answer questions. There are a couple of very important isssues I believe you should give serious thought to WRT an unleaded gasoline for piston powered aircraft.

1) Any required modification that reduces performance is pretty much a non-starter. OTOH if you come up with a fuel that requires simple and inexpensive alterations that do NOT affect performance (e.g. horsepower, full power and cruise power BFSC) I think that would be acceptable to the market. Even a small performance change would require modifications to the operating handbooks for all affected aircraft and that would be a huge undertaking, especially considering that there are plenty of aircraft flying today whose manufacturers no longer exist.

2) Very few airports will ever be willing to offer multiple avgas types, it's simply not economical. It's not like the automotive world where retailers often provide two or more choices. Thus the only viable way for multiple unleaded fuels to exist in the marketplace is if they're completely fungible. You might think that pilots would simply choose to fuel at airports providing their favorite avgas but that's not plausible either for a number of reasons.

Both of these issues are pretty unique to aircraft fuel, primarily due to the heavily regulated nature of flying. If this fuel was for a boat, it would be a very minor annoyance if one's boat engine needed the timing retarded a few degrees even if that meant the power output dropped several percent. Boat operators who want to retain the original power output can utilize boutique fuels for the times when that's needed, and since boats are often fueled via portable tanks it's feasible to seek that out. Since there are no regulator hoops to thread it's much easier to comply with whatever changes are needed.

Hello Al,

Certainly each of the fuel developers has motivations. Here's my take on each, in chronological order.

What motivates the three contenders?
1) Swift began as a passion project of a new pilot, but having accepted VC money, evolved into an effort to identify a solution to protect that investment. The original passionate guy was eased out.

2) GAMI wants to protect their turbo market and customers, and support GA going forward, particularly the personal flying of the two founders.

3) Lyondell began with the solution in mind: better utilize their ETBE manufacturing capability. They’re not searching for the best unleaded avgas, they’re seeking an outlet for their manufacturing capacity.

Does that help?

Paul

Hi Dan,

You started out OK, but limited the constraint space a little bit. Don't worry, that's been done a LOT in the pursuit of unleaded avgas! :-)

Fuel cost is yet another constraint. Swift's original formulation, with mesitylene, appeared to offer no performance compromises... they just didn't have any folks on board that understood gasoline blending well enough. I gave them some pro bono help, but pearls before swine and all that (lots of hogs in Indiana!)

My modeling showed that a more GAMI-like or Lyondell-like Swift fuel, with mesitylene and some xylenes, and high-octane alkylate, wouldn't require the aromatic amine additive. The kicker, and what really killed the first Swift effort, was manufacturing cost. Their contract engineer, a guy I knew professionally, got "fired" from the project for honestly answering a question at a press conference at Sun 'n Fun 2012. "What will the Swift fuel cost be, including capital recovery, etc.?" Oh, about $10/gallon. Nobody liked that answer... avgas was at a local low then, about $4.

I've been watching this drama play out since the FAA launched the CRC group in 1991. It's kind of a case study in how NOT to run a major project.

Paul

Hello Al,

Certainly each of the fuel developers has motivations. Here's my take on each, in chronological order.

What motivates the three contenders?
1) Swift began as a passion project of a new pilot, but having accepted VC money, evolved into an effort to identify a solution to protect that investment. The original passionate guy was eased out.

2) GAMI wants to protect their turbo market and customers, and support GA going forward, particularly the personal flying of the two founders.

3) Lyondell began with the solution in mind: better utilize their ETBE manufacturing capability. So like the little kid with a hammer, every problem looks like a nail. They’re not searching for the best unleaded avgas, they’re seeking an outlet for their manufacturing capacity.

Does that help?

Paul

One could say about the same for Lanxess and m-toluidine.

One could say about the same for Lanxess and m-toluidine.

No bias there, whatsoever.

One could say about the same for Lanxess and m-toluidine.

I don't know the specifics of your relationship with Lanxess.

Lanxess and employees are mentioned as co-inventors on several G100UL related patents.

Which is the only reason I know about them.