Denny,

I completely agree with everything you said.

If however, there's a chance that the owner might occasionally start
the engine around 40Fdays without pre-heating (not exactly a temp that
normally requiring pre-heating), the Phillips X/C 20W50, at only $40 a
case, would be a better choice than Phillips 100AW or 100AD.



Denny wrote:
Pete, I have no criticism of your determination to maximize engine
longevity... I have a pair of engines I'm babying along...
Yes, I have rebuilt aircraft engines sob, sob...
Let me play devils advocate here based on the additional information
you have given to other posters..
1. you run the engine regularily..
2. you preheat in cold temps...
So, let me be the first to say you are wasting your money on
semisynthetic, multiviscosity oils! Yes, wasting your money, kemo
sabe...
You should be using a good, single viscosity oil, changing the oil
religously at 25 hours, and your filter at 50 or 75 hours... Having
that bright, golden, fresh, slippery, oil in the engine will do more to
prevent wear than anything else you can do...
Every branded oil company has an excellent, single viscosity, petroleum
based oil, with Lycoming additive that they can barely give away... An
industry secret that FBO's know... Let me suggest Phillips 100AW at
less than half the price of 15W50, or 20W50 as a good oil to use...

Now, this advice does not apply to engines that routinely go weeks
between starts, that are started stone cold, etc.. There a
semisynthetic, multiviscosity oil is probably the best - actually a new
owner that runs them often is the best, but it's an imperfect world...

The other habit I would forego is ground running... More engines than
you can wave a stick at are burnt' up getting the oil temp "into the
green"... By the time you run up and taxi to the runway that engine
is ready to go..

The last comment I will make on this is that changing oil brand/type is
guaranteed to obscure the analysis for 2 to 4 changes...
No, I don't do oil analysis... I change my own oil, I cut open my own
filters, i clean my own plugs, and I listen to my engines... Not
perfect, but it's an imperffff, uhh, geez the echo in here is
deafening...

denny