I won’t be pasting a link that discloses my base of operations or any similar info, thanks.
LeSving wrote:
how do you explain this report taken data from several other airports with obviously less traffic than your home airport?
The paper indicates that lead concentrations near a very busy GA airport are often higher than those away from that airport. That was also true for the data near my base, so I guess at least they knew their instrumentation was working. However the EPA data for monitoring locations expected to produce the highest levels around the airport perimeter did not at my base produce levels that exceed the US national standard for lead in the atmosphere, as I explained.
Many airports in the Nordic are now on their way to get rid of 100LL. We took a round trip Baltic up to Finland and back and had serious challenges to get the needed Lead stuff for the Cirrus. Saying was they try to get it out of their countries by the end of this year. Next trip I will go with the C182 to be able to slurp UL91/94 …
I wonder how long till its available in the Europe.
Just another regular day; hell is frozen, pigs are flying, and the FAA approved a fleet wide STC for unleaded fuel.
Congrats to GAMI and kudos to Paul from Avweb for exposing FAA’s ridiculous foot dragging on the issue.
Now let’s see what EASA does. Would they be able to declare G100UL a direct replacement? Mandate its use over environmental concerns?
https://www.avweb.com/ownership/fuel-news/gami-unleaded-avgas-stcs-approved-for-ga-piston-fleet/
I wonder what the secret ingredient is. A google search gave this (but could be just nonsense for all I know):
It seems the fuel, for various reasons, can’t meet the D910 specs that 100LL is produced under. But that does not seem to matter. The FAA does not certify the fuel. The FAA certifies what the engine/airframe manufacturer requires for fuel. G100UL contains 20% xylene and that increases the boiling point (end point) about 8 DEG F beyond D910 specs. (That won’t matter, and is not operationally a problem, as that spec was made in the 1930’s and we know a lot more about fuels now) .
The fuel contains:
Isopentane
Aviation alkylate
Mixed xylenes
m-toluidine nitro-amine octane booster, GAMI found a benign amine that works well. It supposedly comes from a product used in the “ink” industry and is produced by a Bayer offshoot company. Maybe it’s similar to PEA that is used in Chevron Techron and that helps keep combustion chambers clean, as after 170 hours, the combustion chambers of normal engines are loaded with carbon.
According to that, it is basically ink 
There’s no single secret ingredient, it’s a custom designed mixture to achieve the desired properties.
Arne wrote:
There’s no single secret ingredient, it’s a custom designed mixture to achieve the desired properties.
That is a typical not-answer Increasing the octane has to be done by some specific ingredients not normally found in ordinary fuel from a refinery (ie “aviation alkylate”). m-toluidine nitro-amine may very well be it, as shown in this document#:
The composition shown, and with 7 % m-toluidine, will give RON and MON of both 116. Probably more than adequate for all aviation engines?
