93 NE fuel sources lost!

[Johnny C!]

I have been able to get 93 non-ethanol
in my 912UL, before now, but it that
distributor has stopped carrying it. I
am currently looking for other nearby
sources, but if I don't find anything,
has anyone here use the 90 NE. Most
gas stations have that in my area.

I guess I will have to consider mixing the
two, but that's more hassle.

I wanted to see if anyone has been using
the 90 NE.

Let me know.

John

[gkremers]

John,
When I first started flying the only EF I could find was 90 so that is what I used. After about 20 hours I started getting concerned about the lower octane. I called a highly respected Rotax rep and asked him his opinion on the 90 EF fuel. He said he would much rather see me running 93 unleaded with ethanol. I switched at that time and haven't looked back. 180 hours with zero issues. I don't know if the 90 would untimatly cause an issue but I had to go with the recommendation from Rotax.

Gary

[ScottieB]

I remember reading in the Rotax manual for the 912S that they actually recommend 95 octane gasoline. We run 93 simply because 95 is not available to us. If I run into a situation where I can no longer get 93 octane then I suppose I will mix the lower octane automotive gasoline with 100 octane Avgas. Make no mistake - spark knock WILL destroy your engine.
That being said, John, I believe your engine is a lower compression model and therefore the octane requirements may not be as high. It would be worth doing a little digging to find out what Rotax recommends for yours.

[gkremers]

I believe the operator manual for the 912ULS Specs

Min RON 95
Min AKI 91

91 is what you read on the pumps in the US

Article below from Sport Pilot

What does MOGAS RON 95/AKI 91 mean?
The Antiknock Index (AKI) is the octane rating usually used in the US. It is the number displayed on gasoline pumps in the US and is the number used by automobile manufacturers in specifying the octane requirements of their engines. Rotax specifies a minimum AKI of 91 for the 912ULS. The AKI is determined by averaging the RON and the MON using the formula AKI = (RON + MON) / 2.
In Europe, RON is most commonly used to specify octane rating. This is the source of some confusion among owners of some European cars. Fuel with 91 RON in Europe is roughly equivalent to 87 AKI and fuel with 95 RON is roughly 91 AKI. So a Rotax 912 ULS powered aircraft sold in the US and requiring 91 AKI would be specified as requiring 95 RON if it were sold in Europe.
The use of Premium Grade auto fuel is approved for the Rotax 912ULS aircraft engine.
Refer to the Rotax Operator's Manual section 10.2.2 Fuel, Rotax Service Instruction SI-912-016 for the most current information.

[Johnny C!]

912 UL 80 horse.

89 minimum recommended by Rotax.

I have found another new source for
93 NE, and I will need to go check
at another station closer to me than
the first.

So I will roll with 93 again.

Thanks for the comments.

John

[gkremers]

John,
I had the 912UL in my PulsarXP, great engine and more fuel options.

Gary

[danerazz]

(Sarcasm warning)

All of the great benefits of ethanol and you guys are trying to undermine the whole system.

[scubarider2]

I can get 93 nonethanol pretty much all year except middle of the winter when the store closes for the season. I usually at that point get the 89 octane and do the octane booster additive until the store reopens.

[Johnny C!]

I don't know if it was a coordinated event,
but apparently, as one distributor was
dropping the 93 NE, another picked it
up, so I am back in business.

I put in 10 gallons of 100 LL at Transylvania
last night, and it was $6.18 per gallon. Yowsa!

All is well again.

John

[gkremers]

John,
Just a question. With the 912 (80 HP) why are you concerned running 90 EF?

Gary

[Johnny C!]

Gary,
I was told before my maiden that
if the 90 octane gas sat for too long
in the station's tanks or in mine, it
could gas off enough to be below the
required 89 for my engine.

I ran nothing but LL while test flying
& tweaking (not twerking!) at Troy's
suggestion because of the likelyhood
of it sitting on the tarmac for longer
periods of time. And it did sit for a
while a few times, so the LL then
worked well for me & Scott.

So 93 is a bit of an insurance policy.

If I did lose all of my sources for 93, I
would have probably started mixing in
a percentage of 100 LL with the 90, to
give me a safety margin.

John

John,
Just a question. With the 912 (80 HP) why are you concerned running 90 EF?

Gary