ethanol-free high test gas

A couple of local gas stations have begun carrying ethynol-free high test gas. Seems like a good choice to me for the Rotax 912. Any thoughts?

IMHO, any engine is better off with ethanol free fuel-----not just Rotax.

I just bought some ethanol free high test as well, but I am not sure that I will use it. I am in Kentucky, the high test ethanol free is only 91 octane, whereas the 10% stuff is 93. Be careful what you buy!! Tom

Ethanol free if possible

Here in upstate NY one supplier just started advertising Ethanol free premium. Most times there's a line to get gas. Ethanol is destroying engines at a alarming rate. In Massachusetts their ramping up to 15% Ethanol. Ethanol even destroys the equipment that delivers it. If it wasn't for the government subsidy on every gallon and the group that thinks their saving the world by burning up our food for fuel this would never have become a problem. Try a tankful in your car. You'll be surprised at the added MPG.

todehnal said:

I just bought some ethanol free high test as well, but I am not sure that I will use it. I am in Kentucky, the high test ethanol free is only 91 octane, whereas the 10% stuff is 93. Be careful what you buy!! Tom

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If I am not mistaken, Rotax specifies a minimum of 91 octane for our 100 HP engines. Check SI-912-016R6.

sandpiper said:

If I am not mistaken, Rotax specifies a minimum of 91 octane for our 100 HP engines. Check SI-912-016R6.

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So here is a question, Love's and a few other stations near me, sell 100 (and I have seen 110 and 114 as well) E0 Racing fuel for the local racetracks.

Since 100LL is "legal", is 100 E0 Racing Fuel "better" or "safer" than 93 E10 available at most regular stations?

Fresher is probably better I agree, but I have seen some knocks against Costco and some others for so-called additives that may be harmful, yet clean, so they have fresh and stable going for them....???

Ive run 91 octane, no-ethanol since first start, no issues. I would not hesitate to run ethanol in it though, but I can get the no-ethanol locally. I get it 10 gallons at a time and put i in a 15 gallon fueler with crank pump. I run it through a Mr Funnel when putting it into the fueler. Ive never gotten more than a drop of water out of the gascolator drain.

You guys are correct. The Rotax SI states 91. I was going by the POH from Van's, which says 92 minimum. Ethanol free 91 is available here, and I will start using it. Thanks.

Tom

caution

As always in these discussions, please remember that "octane" is measured in different ways by different people.
AvGas is measured by "motor octane"
car gas is measured by the average of motor octane and "research octane" (R+M/2)
Typical 91 car gas comes in at 87 motor octane.
Typical 100 octane car as is not the same as 100LL; it's about 96 motor octane.

Hopefully Rotax specifies 91 "car gas" or equivalent.

Thats a well-known typo in the Vans manual.

todehnal said:

I was going by the POH from Van's, which says 92 minimum. Tom

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I just checked my recently received copy of the POH (rev 5). Section 2 (2-2, rev 2, 12/18/12) says 91 AKI Premium, but Section 8 (8-2, rev 1, 11/13/12) says 92 AKI (premium).

I have been hauling in 100 gallons of 91 ethynol-free for the last year. Run ethynol - free also in the motorcycle, snow blower, generator, etc..

That ethynol is nasty

For the RV12 I only fill with 100 LL when I have to due to being away from the home field and change the oil earlier if I do.

How do you locate these stations with the ethanol free mogas? Is there a website?

http://pure-gas.org/index.jsp?stateprov=CA

California is one of the lightest states for EF fuel

Anyone else interested can substitute their state in place of the CA in URL

Ethanol Usage

If you can find ethanol free fuel you are an exception and we all wish we could, but...

Ethanol laced 91 oct. is a far better choice over 100LL for your average flying just because of leading, not to mention all the extra maint. Rotax has published that 10% is okay to use because that is all they have tested, but in areas in Central and South America they use up to 22-23% ethanol and have been for many years without any issues. They just recently tore down a 1400 hr. engine and all was good. So the engine doesn't care. Our fuel hoses today are good otherwise all our cars would be parked and disabled along side the road. So if your fuel tank can handle the ethanol there is no REAL reason not to use it. Water absorption should not be an issue because it should not have anyway into the tank other than through a tiny vent hole or you poor it in and your fuel was trash to start with. I have demonstrated this by poring a class of water into a fuel tank and still running the engine. If you ever see standing water in ethanol fuel it's time to get rid of it because that means it is fully saturated. The ethanol can absorb water up to a certain point depending on volume and still run. Yes you do not want it in there and living a in a humid climate and worrying that the fuel will suck up enough water to kill the engine isn't realistic since it has to go through a tiny vent and the fuel is off gassing through that vent all the time anyway. I have yet to actually meet a person that had a proven case of phase separation. It's possible, but not very likely. Many areas in the world and the US use ethanol in the 912 and have been for many years without any issues. People tend to over worry.
I have heard all the claims about ethanol, but it hasn't been an issue for the ones that use it on a regular basis.
My guys at my field test every batch and we are supposed to have 10% here in Tucson, AZ, but it only really has 6-7% and the highest we have seen is 8%.

I'll use 91 Oct with ethanol any day over 100LL and all the lead damage it causes and all the extra maint. The only time I'm stuck with 100LL is when I travel.

OK, what brand in KY??

Hope it's available 60 miles north of the river. My Marathon 93 octane test e-free with the blue additive, but about 5% with the water test. Been usiing it for 3 years.

Wayne 120241/143WM

We have 90 octane no ethanol available here. Is that close enough?

Bob

In September ROTAX released a revised SI with a minimum octane of 91 AKI by US standards. If I was in your shoes I'd try the 90 if it was the only thing available, but realize it's outside the manufacturer's recommendation and closely monitor the engine parameters until I was convinced there isn't an obvious issue. That being said you're definitely experimental if you are outside the ROTAX tested parameters.

Bob, I should have also said that the SI referred not only to an AKI 91 , but also a RON 95 value. I have seen the RON values on the pumps in Phoenix, but not the AKI value, so I'm not sure which method your 90 adheres to. I don't think it would change my approach, but thought I should add the info.

Rich

BobTurner said:

As always in these discussions, please remember that "octane" is measured in different ways by different people.
AvGas is measured by "motor octane"
car gas is measured by the average of motor octane and "research octane" (R+M/2)
Typical 91 car gas comes in at 87 motor octane.
Typical 100 octane car as is not the same as 100LL; it's about 96 motor octane.

Hopefully Rotax specifies 91 "car gas" or equivalent.

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Further research here on the local available gas indicates R+m/2 = 91.

I'll have to study more to see if that's acceptable...

Bob

Bob,

Your post made me take a closer look at my pump. I've been burning 10% ethanol RON 91 for about 115 hours with no problems.
$1,700.30

Rich

Measuring Method

Rotax specifies 91 octane using the (R+M)/2 measuring method. Hope that clears this up. Tom