That's what I've heard. Some aircraft engines need to be aggressively leaned to avoid lead fouling.
And it's (100LL) very expensive, especially when you don't really need to use it....

Help us flyers get UNLEADED mogas! Put yourself on the map, maybe I'll stop in your town! http://www.frappr.com/mogasassistancenetwork

----
??? Lead deposits are the #1 cause of fouling in aircraft engines.

Hans

al p wick wrote:

On piston engines the excess lead does not show up on plugs. That's why he doesn't refer to it. I sent him brief note encouraging testing with rotary, as it would be good test of his new formulation. Either you or Perry would be great test cases. Perry because he is so much more sensitive to lead.
http://www.decalinchemicals.com/