Originally Posted By: cappilot
FWIW, according to Wikipedia, 93UL is an ethanol-free premium auto gas, while 94UL is essentially 100LL without the lead.
I think lead-free avgas will do good things for the piston-engine side of aviation. Environmental concerns aside, my guess is that spark plug life will increase dramatically. valve problems will decrease dramatically, engine oil life will be extended, and engine life will be prolonged. (Gee, where have I heard of those things happening in the past? Perhaps the automotive industry?) A crowning touch would be the use of detergents in avgas in the same fashion as car gas. Morning sickness in Lycomings could become a thing of the past almost overnight.
Morning sickness in Lycs is a stuck valve and no engine with morning sickness should be flown until the situation is remedied. Usually involves either doing the fishing line trick or yanking the jug. Saw this many times when I flew though MY engines were all TCM, so I never had that problem, though I did have one stuck valve. It was just gunk, not lead like it usually is in Lycs.
