Total’s new unleaded avgas UL91 (see article in LA August 2011) is now available at many UK airfields, prices appearing to be around 15 to 20p per litre below that of 100LL.
The fuel has been promoted as being particularly appropriate for Rotax engines, but it is suitable, and approved, for a wide range of engines types used in LAA aircraft.
The LAA Airworthiness Approval Note (AAN) for use of UL91 in appropriate LAA aircraft can be found here. It contains a list of the most popular types of engines for which the fuel is suitable.
The EASA document pertaining to use of this fuel in non LAA types is available here.
Fields currently stocking the fuel are: