There is quite a bit of evidence that there is a compromise in wear
protection to obtain the mulit-viscosity. We switched to 100W for the
late
spring, summer, and early fall. It was no big deal, just pick up a
different case and put a note on the old one in our locker. It's probably
only a small wear increment but it made me feel better to have the best
oil
in the engine during the hard flying months.

I aim to change my oil every 25 hours. In real life, this means anywhere
from 25 to 40 hours, depending on how much cross-country I'm flying at the
time.

I change (and check) the filter at every oil change, even though you only
have to change it (and the oil) every 50 hours.

As a result, I'm not concerned with the wear protection difference between
multi and straight-weight oil. I am, however, concerned about the lack of
lubrication caused by the sudden temperature swings we get in Iowa.

Example: Last week it was 75 degrees here . This morning it's 19.

Multi-viscosity takes care of that problem.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"