This come up yesterday from the manufacturer,
“does not approve the use of GAMI G100LL fuel in Cirrus SR Series airplanes. Additionally, Cirrus does not warrant or represent in any way an operator’s use of the GAMI G100UL fuel in Cirrus SR Series airplanes.”
It’s not just Cirrus
Cirrus further advised operators: “Per Continental and Lycoming, only approved fuels may be used for an engine to be covered by warranty. As the GAMI G100UL fuel is a non-approved fuel per Continental and Lycoming, engines known to have run this fuel may not be covered by the OEM engine warranty. For specific details, please refer to the respective Continental and Lycoming engine warranty documents.”
Cirrus may be the only airframe mfg so far to have drawn attention to this.
The airframe manufacturer and buyers can sign whatever purchase/warranty contract they want, and the manufacturer can issue service bulletins, but none of that is law – Cirrus and other airframe manufacturers do not create US law. The fuels approved in the FAA airframe TCDS or an STC applicable to a given airframe are what is legal, and that cannot be changed by anybody (one way or the other) without FAA approval and a new revision of a government document.
Silvaire wrote:
The fuels approved in the FAA airframe TCDS or an STC applicable to a given airframe are what is legal, and that cannot be changed by anybody (one way or the other) without FAA approval and a new revision of a government document.
Indeed, but – as Cirrus wrote – it may void the warranty. I wonder if Continental, Lycoming and Cirrus have any reason for this other than fear of change.
I imagine they do have a technical reason for protecting their warranty costs, if only ambiguous test data and not a well documented problem, but my point about legality was responding to a preceding post that has now disappeared. Probably better that it did since legality is not the issue raised by the article.
other than fear of change.
Or you could call it prudent management of risk 
At work (electronics) when I do a significant change in a product, I introduce it into a small number which are covertly marked to make sure they go out only to small customers, over say 6-12 months, first. This is because a big customer is capable of terminating your business.
This warranty policy is something which IMHO should have been foreseen, but seemingly was not. It is obviously capable of killing off these new fuels. I am sure Lyco and Conti are not stupid and they must have decided that there “might” be something in G100UL which could be a problem and needs checking, but they did not feel the same way for 91UL (which is supposedly just 100LL without TEL), 94UL or 96UL. The last two must have some additives relative to 91UL.
Peter wrote:
Or you could call it prudent management of risk
Clearly. A new fuel with questionable ingredients (it’s an ink product that most producers of ink already has stopped using, an aromat which is not wanted in the chemical industry anymore), is a potential can of worms. The key ingredient may not even be available in quantities and at a price worth considering in 5 years.
As long as true and trusted 100LL is available, why would anyone really go for an unknown substance, that has potential for going bad in all sorts of ways ?
it’s an ink product that most producers of ink already has stopped using, an aromat which is not wanted in the chemical industry anymore), is a potential can of worms. The key ingredient may not even be available in quantities and at a price worth considering in 5 years.
Is the formula known? I thought it was still under an NDA. What are these chemicals?
Isn’t the problem that the recipe is not known, even to the people that check these things on behalf of the FAA.?
GAMI are licensing “blenders” so the exact formulation is known to several people, and will eventually become common knowledge. I assume GAMI will share this information with Cirrus if they have not already. GAMI said that they have sent Cirrus (among others) barrels of fuel to test, but no idea if they have even opened them.
As much as I am a supporter of unleaded fuel, and of GAMI, I think the better solution is to ensure your engine runs on the same gasoline that millions of automobiles use, for the highest chance of success in the market, and the lowest cost. Sure this will be painful for the 130 thousand or so owners that need to modify their engines. It’s not rocket surgery.
