I found a service station in our area selling 110 R+M/2 racing fuel. It is 13 bucks/gal. What are UL engine owners finding that works in this engine? I know of using an additive to combat the lead in 100LL but am curious about mixtures of fuels.  Thanks in advance. Tom Sullivan

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Hi Tom,  I'm using regular 93 octane auto fuel w/10% ethanol.  Not sure how I'm going to handle x-c trips yet.  I am thinking will mix 91 octane with a bit of 100LL if I have to.  Some have claimed to run lower octane without issue, (e.g.; 91  octane auto fuel) but I would be very reluctant to try that. In my mind, based on what I'm reading and hearing from others, worse case would be to run 100LL exclusively.  The CHT's do not get hot enough to burn lead deposits.  Ray Lawrence,  the UL guy down in Georgia with Kaolin Aviation would be a good person to query regarding fuel and lead with our UL engines. HTH!


Thanks David. Sounds like a mix of auto and 100LL is a good option. ON new engines, I've read that some lead should be in the fuel initially to help with the valve seats.

I've been running 93 non-ethanol in my 260i for over 200 hrs.  have run 100LL with "Decolin" additive when traveling.  Just started running 93 with 10% ethanol in one tank.  No change in CHT/EGT,  Just keep flying it, don't let entanol fuel get old.  Have scoped the cylinders and they look "bristol"        Cheers,,,,,,,,  Lynn  


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