Piper Completes Flight Tests of Archer Fueled by 93 Octane

[Aaron Novak]

You're not?
They sure had no problem shoving 10%, and now 15% ethenol down our throats.
Older engines and even gast stations are being affected by it.

No Im not. Aviation is fortunate enough to have a regulatory body that provides a checks and balances system against other regulatory bodies. This does not allow one or more groups ( the EPA/oil companies, whose objective is questionable ) to force anything without the aggreement of the FAA ( whose objective is safety ). The automotive and small engine world does not have this and we are at the mercy of whatever foolishness the EPA/oil companies hand down, even though we travel to washington to lobby against it. This is why I keep saying that the aviation world is actually very fortunate. There are thousands of fuel related engine failures yearly in the auto and powersports markets, yet they have no ability to prevent the EPA and oil companies from doing whatever they wish. No regulation+no control=no predictability, and predictability is exactly what you want when your life is on the line.

[raytoews]

A lot of really interesting technical talk, but experience has taught me, it works just fine.

Test for alcohol on each tank fuel and go fly.

Ray

[Ried]

Recently my auto shop reminded me of the "Top Tier" gasoline retailing organization. http://www.toptiergas.com/index.html

As consumers, we need to look at more than the price when purchasing fuel.

[PaulMillner]

What were you saying about AKI, OICU812, C3-PO and all that?

Thanks for sharing your source material, I Fly... yeah, you did mistate the gasoline octane.

Your O320 is approved for use with 80 octane avgas... that is 80 Motor Octane Number (MON).

That equates, roughly, to a mogas AKI (pump octane) of 85... so as you know from the EAA and Petersen STCs, you can operate your aircraft on conventional regular mogas, without ethanol, as long as you have the STC and have complied with any conditions (some low wing airplanes need additional fuel pumps, etc)

You were calling that 87... but the 87 in 80/87 is the rich supercharge rating, which operationally doesn't affect your normally aspirated engine. That 87 number comes from an F4 octane engine, and doesn't correlate well to any other octane numbers, like the MON+RON/2 or AKI that you see at the gasoline station... so it's misleading and technically invalid to refer to that number in deciding what fuel you want.

I believe the Piper of the thread title has a Lycoming engine certified on the no-longer-available 91/96 octane (or 91/98 octane) aviation gasoline. The 91 MON, motor octane number, correlates to a mogas octane of 96, which you won't find anyplace but a gasoline station that sells racing fuel. However, Petersen Aviation has an STC for those Lycoming 91 octane engines to run on premium unleaded ethanol-free mogas. I don't recall the minimum octane they specify, but I think it's 93 AKI, pump octane, which brings us back to my original comment... it's difficult to find that stuff ethanol free. It's nearly impossible to find that stuff in the West.

Ignorance isn't bliss when it comes to engine octane numbers. People who just shrug and say, "gasoline is gasoline" can end up off airport in a field somewhere, with a hole burned in a piston.

Paul

[Mike M]

.... However, Petersen Aviation has an STC for those Lycoming 91 octane engines to run on premium unleaded ethanol-free mogas. I don't recall the minimum octane they specify, but I think it's 93 AKI, pump octane, which brings us back to my original comment... it's difficult to find that stuff ethanol free. It's nearly impossible to find that stuff in the West....

When in doubt, look it up. don't need 93AKI for Petersen STCs:


http://www.autofuelstc.com/stc_specs.phtml
http://www.autofuelstc.com/

but cost savings? around here we can get 100ll avgas at the airport for as low as $4.87, octane-unspecified-on-the-web mogas at the airport for $4.90, or ethanol-free 90(?) octane boat gas at the local stop&rob for $5.00. name yer poison, pilgrim. your mileage may vary.

[Aaron Novak]

Unfortunately past experience with auto fuel does not mean squat in the future. Mogas is ever changing, ASTM testing methods change, and there is no way of knowing for sure that the fuel you bought at the local gas station meets ANY specs. Heck we have had 93 octane pump fuel measure in at 89. 30 years ago when the STCS first came out, Mogas was a better fuel......times have changed, and not for the better as far as MOgas for aviation is concerned.

[JimRice85]

Around here, 100LL is $5.50. Ethanol-free Mogas is $3.90.

[I_FLY_LOW]

What happened to the big push for using ethanol in planes?
Seems like in 09'Airventure, IIRC, that they had a couple airshow pilots, plus a few other exhibition planes that were pushing the E85 fuel.
I wasn't interested then in the idea, but wondered now, because I haven't heard much about it, lately.
Did it get quietly swept under the rug?

[Mike Berg]

I owned a Cherokee 140 with a 0320 for over 25 years. During that time it consumed a lot of 'mo-gas' with absolutely no problems. I had more trouble with 100LL fouling the spark plugs no matter how many different techniques I tried. Using 100LL was OK for longer trips but doing any amount of 'airport hopping' (short and any amount of taxing) was sure to cause plug fouling. When we pulled the plugs on annual they were always filled with balls of lead that resembled solder. Never had vapor lock either but then was consistant about using the electric fuel pump on take off and landing and it has a fuel pressure gauge. That engine now has over 1500 hours on it since overhaul and still performing well. I will agree there might be some concern with detonation with the higher compression engines but the 0320 is only 7:1. Ethanol is another story at this point in time due to possible breakdown of fuel system components.

[PaulMillner]

When in doubt, look it up. don't need 93AKI for Petersen STCs:


http://www.autofuelstc.com/stc_specs.phtml
http://www.autofuelstc.com/

but cost savings? around here we can get 100ll avgas at the airport for as low as $4.87, octane-unspecified-on-the-web mogas at the airport for $4.90, or ethanol-free 90(?) octane boat gas at the local stop&rob for $5.00. name yer poison, pilgrim. your mileage may vary.

Let's see... it says, "91 Octane Minimum"

But then... note the thread title, "Piper completes flight tests of Archer fueld by 93 Octane"

It seems we have a disconnect here...

Of course, in parts of the mountanous west, even 91 UL is difficult to find... RUL is 85... MUL is 87, PUL is 89...

Paul