WHAT? No more 93 non ethanol? Only 89

[Bob H.]

I never heard in advance that our options for fuel were reduced again! I went to buy 93 non ethanol at my usual place and was told regulations changed the first of the year and 93 will no longer be produced, only 89. I was told the octane level is actually a bit higher to guarantee at least 89 after sitting 6 months.

They also told me that the 100ll is 107 when newly produced to insure after sitting it remains 100 or above.

Comments?

[Michael W.]

Re: WHAT? No more 93 non ethanol? Only 89

Comments?

I think you listen to 'they' too much. Why not use 91AKI E10 like everybody else?

[John D.]

Re: WHAT? No more 93 non ethanol? Only 89

Bob, Google: Pure-gas.org Click on your state to find out what stations have pure gas and what octane is available. Problem is the list isn't always updated. John

[Duke W.]

Re: WHAT? No more 93 non ethanol? Only 89

Refineries typically produce gasoline blends that are designed for ethanol blending, which is an octane enhancer, so the desired octane is obtained after the ethanol is added at the distribution point.

It would be highly uneconomical for a refinery to produce small batches of gasoline that achieved 93 PON without the addition of ethanol.

100LL (Aviation Method) is approximately equal to 100 MON, which is approximately equal to 108-110 RON, which is approximately 104-105 PON (AKI). After all the TDB posts and NCRS presentations on the different octane rating methods and how to convert (approximately) one to another, I'm surprised that many still don't have it straight.

The bottom line is that everyone has to determine on their own what commercial or custom "blend" of gasoline their engine configuration and "tune" requires to operate without significant detonation. There are no hard and fast rules because there are too many variables. It's a matter of individual experimentation.

I've recommended to several that they experiment with lower octane and all reported that their engine ran without detonation on less than the highest octane available. I each case the thick head gasket I measured and the fact that is was known that the engines had been rebuilt made me suspicious that they had been rebuilt with "lower compression".

It's a very simple test to conduct.

Duke

[Joe L.]

Re: WHAT? No more 93 non ethanol? Only 89

Refineries typically produce gasoline blends that are designed for ethanol blending, which is an octane enhancer, so the desired octane is obtained after the ethanol is added at the distribution point.

It would be highly uneconomical for a refinery to produce small batches of gasoline that achieved 93 PON without the addition of ethanol.

100LL (Aviation Method) is approximately equal to 100 MON, which is approximately equal to 108-110 RON, which is approximately 104-105 PON (AKI). After all the TDB posts and NCRS presentations on the different octane rating methods and how to convert (approximately) one to another, I'm surprised that many still don't have it straight.

The bottom line is that everyone has to determine on their own what commercial or custom "blend" of gasoline their engine configuration and "tune" requires to operate without significant detonation. There are no hard and fast rules because there are too many variables. It's a matter of individual experimentation.

I've recommended to several that they experiment with lower octane and all reported that their engine ran without detonation on less than the highest octane available. I each case the thick head gasket I measured and the fact that is was known that the engines had been rebuilt made me suspicious that they had been rebuilt with "lower compression".

It's a very simple test to conduct.

Duke

Duke-----


There is only one company in the world that currently produces tetraethyl lead for fuel and they do so in a single plant. By the end of this year, they are going to cease manufacturing it for automotive fuel. They wanted to be out of the business at the end of last year but a few countries dragged their feet. They will keep manufacturing it for aviation fuel "as long as necessary". However, they want to get out of the business entirely and are encouraging the aviation industry to come up with an alternative. The EPA is, of course, basically demanding the elimination of lead from avgas. So, the days of any sort of leaded fuel are very numbered.