”Stan.Cooper” said:
Paul, he says he flies a Piper Archer 2. If it's a 181, the engine is a Lycoming O-360-A4M.
Thanks Stan, I’d missed that… and wouldn’t have known the exact engine designation without your help.
”FlyingRon” said:
It's all kind of moot until someone gets a distribution system for their alternative fuel.
Well, of course, Swift has a distribution system for their 94UL, the fuel asked about by the OP. The question is how reliable it has been, and will be. When it comes to the 100UL fuels, the five contenders all have distribution plans, whether simply supplanting their existing 100LL system, or via ad hoc systems. The ad hoc approach is much easier to accomplish with an unleaded fuel, of course, than conventional leaded avgas. I think given approval, worst case will be a year spinning up the distribution, given the work done to date.
Aircraft are certificated to burn specific types of fuel and I don't think any current airplanes list Swift as one of the options.
Take a look at Lycoming’s current service information on fuels applicability to engines:
https://www.lycoming.com/sites/default/files/SI1070AB Specified Fuels.pdf
They do not specify by manufacturer (Swift, Exxon, BP, Phillips) but rather by octane, and by type of fuel, in this case, avgas. For the O360A4M that Stan has pointed us at, Lycoming says any avgas 91 motor octane or better. That would include the referenced Swift 94UL, and the ill-fated and never produced (but certified) Amoco 92UL (IIRC). If you look at the service instruction above, you'll see the subject O360A engine is approved for 94UL...
I’m not certain if Piper has been as open-source-oriented in approving fuels for their airframes, but with the right FSDO, a field approval for an airframe, given the engine approval, could be straightforward. Or… you could buy the STC. Your choice!
”Chip.Sylverne” said:
What's the price where available?
I just called SQL, San Carlos airport south of San Francisco, and they’re discontinued 94UL. So I tried calling LAF, Swift’s home field. They say they haven’t seen any in a while. Hmmm. IIRC it sold for about 20 cents per gallon above 100LL, back when you could get it. There’s a rumor that Swift is in financial trouble. I asked their CEO about that, and he replied angrily, but didn’t exactly deny it either. I’ve asked him a follow-up question about the airports that used to have 94UL and now don’t.