T&T: Lehman Multigrade v Monograde Oil

[Steve Anderson]

This gets closer to my question.  The "why" of  single viscosity oil use.
However, multi viscosity oils are recommended and used in millions of trucks
and other applications that would suffer the same degradation yet there does
not seem to be the same level of debate.  Perhaps I just not listening.  Also,
does anyone know how long this supposed process takes before there is a
significant loss of lubrication.  Most of us are changing oil every 100-150
hrs or so.  That's not a long time.   And last, it seems that there have been
huge advances in oil chemistry since our Lehmans were made in the early to mid
80's.  Maybe, there would be a different recommendation if they were being
made today.


Steve Anderson

<Multi grade oil has chemicals added to a low viscosity oil that increases its
viscosity.   The longer the oil is used, the more they get broken down and the
lower the viscosity gets until it reaches the viscosity of the base oil
used.>