At 04:30 PM 7/21/2016, you wrote: >Thanks for that great summary Jeff. I've been tossing up on running >automotive oil in my O-200 (which only ever sees 100LL if I'm away >somewhere and it's too hard to get unleaded) but had decided the >saving between a good automotive oil and aviation oil is practically >nil so I've stuck with aviation oil. Looks like the science backs >that decision. Good to know. Cheers, Tony +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
I know nothing about the science of oils other than it is slippery and makes a mess if you get it on your hands, floor, or anywhere else. I can however share 1000 hours of experience with two different engines. The Tripacer had right at 1800 hours (0-320) since overhaul and I flew it an additional 500 hours and it flew an additional 100 to 200 hours after I sold it before it was overhauled. The 0-200 in my KR had 1800 hours on it when I purchased it, it sat for nearly 10 years, and I've put 550 hours on it. I've probably run 50 / 50 100LL and non-alcohol auto fuel at different times over those hours. I've used exclusively Phillips 20W50XC and I've also used Marvel Mystery oil consistently over that period. 1000 hours on high time engines and never a stuck valve and the plugs rarely have any carbon build up. I've only had to replace one high time cylinder as it had an intake valve seat deforming and would only hold 40 pounds of pressure. It was still being flown regular when I found the problem on an annual. I put 1 to 2 pints of MMO directly in the crankcase at oil change time and 4 oz in the fuel for each 10 gallon. I have no way to prove that MMO is beneficial but I'm not about to stop using it. I also knock on wood, cross my fingers, and tap the dash 3 times before pulling the starter T handle. Unless there are considerably different metals used in VW and Corvairs I'd be inclined to treat them as air cooled aircraft engines as they have the same running parameters. As always........ Larry Flesner