Fuels

[Dick B in KY]

Question for the masses: Have you had any problems mixing auto fuel with 100LL avgas (while using Decalin), or switching back and forth? I have a 912ULS and have been using auto fuel (93 octane) but getting ready to switch over to avgas. Thanks for the inputs.

Dick B

[Dave S]

Dick,

Never had any problem with mixtures. I never have a constant ratio - just whenever on a trip and +octane auto is unavailable I fill up with 100LL and add the amount of Decalin per gallons of 100LL according to the instructions on the Decalin jug. Overall I don't average very much AVGAS - probably less than 10%. I believe Rotax indicates any more than 25% 100LL - the more frequent oil change kicks in. One FBO in Iowa premixes 15% 100LL with +octane auto and pumps that for a lot of their experimental types.

The Oil and plugs certainly seem to stay clean with the majority of fuel Autogas.

I just keep the jug of Decalin in the back storage all the time.

When using 100LL - be sure you run semi synthetic engine oil which works with both fuels.

Dave S
KF7 Trigear
912ULS Warp Drive

[Dorsal]

I use mostly 100LL with occasional Mogas, always add Decalin when filling with Avgas, no problems. I also run Aeroshell Sport Plus changed every 25hrs.