Guys  I like to chime in on this subject since I know (a little) about it.

am Jim Etcheverry and I am in the lubricants business and have owned 5
planes from a Taylorcraft to a Aerostar with manuel wastegates. First Bill
is completely right about MobilAV1 and the reason why a Staight synthetic
does not work as well as a semi-synthetic. The "petroleum base" product

a good job of scavenging the "grey paint" caused by the leaded fuel. This

why Shell decided not to offer a 100% synthetic. Next the real  problem

"cold oil" is START-UP. Have you ever heard the Slick 50 ad "it is a
terrible thing to start your engine." All the oil is in the sump and if

notice you"ll have not oil pressure for a moment or so. So LOW RPM at

until oil pressure in up. This is why the new multi-vis oil are great.

like 15w at start-up and performance like 50 at temp. You probably don't
know that the Aeroshell 50w we used to use is the same viscocity as SAE

gear lube. This gives you idea how hard start-up is on the engine. Before
15w50 most of you in cold weather places would use 40w in winter and 50w

the summer. Next "AUTO OIL" DO NOT USE THEM IN AVIATION ENGINES PERIOD.
Aviation engine require Ashless Dispersant oil and auto oil use ash . Ash
when heated ( such as a lean out engine) will form carbon and become
abrasive. You could use auto oil and have no problems if you never got the
oil real hot , but it is not the way to go. I like the new Exxon probuct
because they have extra rust and corrosion protection. They have sited

D 1748 test for rust protection and CrC L-38 test for acid number increase
or corrosion protection. Remember the saying of heating your oil up to 180
to burn off the condensation, these extra additives are exactly what our
plane that sit for long periods of no use need. I have used Aeroshell

since it came out and love it , but this Exxon product really looks good.
Check it out at the next Airshow you attend. Oil is like politics,

has a view point on it. Jim- Schaeffer Mfg.
----- Original Message ----- From: "Bill&Sue" <5zq@cox.net>
Sent: Sunday, April 03, 2005 9:39 AM
Subject: Re: [LML] Re: Oil and warming up


> >  With all these comments about thick cold oil, I' wonder why no one is
> > usingac
> > 100% synthetic, which was given top marks in an extensive test by
Aviation
> > Consumers many years ago... the leading ones being BelRay and ... and
alsohow> > Mobile 1.
>
>
>
>
> Hello Terrence,
>
> If you use 100% synthetic, just be sure not to use leaded aviation fuel.
The
> 100% synthetics leave what is called, I believe, "grey paint". Seems

> they don't scavenge the lead. Mobile Av1 was taken off the market

> years ago because of a large number of problems and law suits over this.
>
> Todays solution seems to be the semi-synthetics such as the multigrade
> AeroShell and more recently Exxon Elite. I have used the Exxon Elite in

> engine for almost 1,000 hrs (except for break-in). It has performed well
and
> allowed easy cold starts. Has all of the advantages that you site above
and
> is designed for leaded avgas.
>
> Bill Harrelson
> 5zq@cox.net
> N5ZQ  320  950+ hrs
> N6ZQ   IV   1%
>
>