GAMI 100UL

Rotax has a document stating the Specifications ie AKI, ethanol content ASTM standards etc required for fuel.

So long as any fuel meets this spec it is "approved" Rotax does not need to name brands of fuel.

If GAMI have not published Internationally recognised Specs (RON/MON/AKI ASTM) then they should....

Hi Gary

An STC requires that people need to get approval, usually for a fee, to use it on any type certified aircraft.  For non-certified it is simply everyone is a test pilot who uses it as there is no direct data on on use in a Rotax.  Rotax will not approve any fuel unless they have evaluated it and there is some market demand.  To my knowledge there is no supply of this in Europe so any approvals would have to be based on some long term running in the USA somewhere and then evaluation as to what, if any, damage or differences might be seen.  This normally is done as some type of cooperative effort with an OEM or Rotax Service Centre who wishes to move approval forward.

Rotax has now given approval of Swift UL94.  If we use that as a guide it takes a few years to proof such a fuel and show there are no major concerns before Rotax will approve it.  

Cheers