Gary:
Interesting response, and one that I cannot find fault with.
I am not an automotive engineer, so I can only go on what
I have read; that the majority of engine wear occurs on startup when
there is little oil on any of the parts. Lower viscosity oil circulates
more quickly, reducing startup wear.
In addition, David Vizard claims that you can have too much oil
pressure, and that too much oil pressure reduces horsepower without
extending engine life. The reduced horsepower comes from the increased
work needed to drive a pump with higher oil pressure.
So, adding to the increased startup wear is the notion of
reduced
power (and by implication, economy) and you have my reasons for using
10W-30.
I am sure this topic will remain controversial. Perhaps someone
can point us to some material on the web?
Cheers,
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Gary Fluke
Sent: Friday, October 21, 2005 11:29 PM
To: Six Pack
Subject: Re: Which Oil Do You Use Anyways?
Gentlemen,
I wonder if seeking a high oil pressure reading is really the goal here.
Oil flow is the requirement. However, the monitoring of our systems is,
of
course, done with a pressure gauge. A flow meter would by nature likely
be
more expensive and troublesome.
You may wish to consider two extreme ends of the operating conditions of
a
pump:
1) When pumping through an open discharge line with a pressure sensor on
the
open discharge pipe the pressure reading will be almost zero and the
flow
will be high.
2) When pumping through a pipe with a very small aperture at it's output
the
pressure reading of the sensor in the pipe will read high and the flow
will
be at a minimum.
Higher viscosity oil is more resistive to flow and therefore replicates
the
effect of trying to pump through a small aperture. It may feel good to
see
the higher pressure reading, but flow cannot be as much as with lower
viscosity oil, all other factors being the same.
Gary
'73
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