Gene Kearns wrote:
On Mon, 12 Jun 2006 06:10:56 -0400, Big gus
wrote:


WOW and thanks for all the advice

another question

lets say we are using strait weigh 50 in the engine
this means it will be "50 weight" all the time



Yes, but it will be thinner when hot than it is when it is cold.


Now....

let say we also got 20W-50
this means its 20 weight when its cold and 50 weight when its 100
degree Centigrade

so ....


Your premise is erroneous..... You came here for help and I'd like to
believe that you didn't fall into the trap of believing the uninformed
foolishness some posters wrote here as truth.

An expert on oil wrote the following:

"Most people believe that a 5w30 oil is good for cold weather use
because it is a "5 weight" oil in cold temperatures and a "30 weight"
oil at high temperatures. On the surface this might seem to make a
certain amount of sense. Naturally, a "5 weight" oil would flow better
than a "30 weight" oil. This would make it ideal for cold temperature
operation.

Nevertheless, this is a profound misunderstanding of what the labeling
means. The two numbers really have little to do with each other."
(Quoted from following URL.)


dos this mean the strait weight 50 and the multi weight 50 are the
same viscosity? ( given the multi weight is at 100 degrees?)


No. They would both have to be at the same temperature and would fall
into the same viscosity range. Leaving that temperature.... their
respective viscosities would diverge.

If you want to know how oil *really* works, here is an easily
accessible web document that, in non-technical terms, pretty
thoroughly covers the subject.
http://www.trustmymechanic.com/motor-oil-bible.pdf

I read the explanation and it is double talk. In fact both numbers are
classifications determined by viscosity, although the process is
different. So a 5w30 meets the specs for both a 5w (cold measurement)
and a 30 (hot measurement) which are both based on viscosity.

So when cold it is like a 5w (not a 5 weight) oil and when hot it is
like a 30 weight. Why he and you can't say that is beyond me.

--
Del Cecchi
"This post is my own and doesn’t necessarily represent IBM’s positions,
strategies or opinions.”