Very interesting; many of the new vehicles now spec the wide viscosity
(5w-30, etc.) oils. . .for example the Corvettes. What are they doing that
is not appropriate for the old trucks? Bearing clearances or materials
maybe? How do change intervals and synthetics play into this as well as you
imply that the shear forces are at issue right out of the can and not as a
result of breakdown with time/heat/contamination? Which This Old Truck issue
was this? What does SAE have publised on this?
I run synthetics in the Jeep and the vette but change more often than
required, just run whatever in the 86 Silverado with 210K miles on it since
it burns/leaks oil, and was planning on running synthetic in the Sub after
the engine is broken in. . .so this is an important topic. Thanks for
addressing it.
Mark Noakes
Knoxville, TN
58/56 Chevy Suburban 2wd V8 3speed w/OD
59 GMC Suburban V8/Hydramatic looking for a 1/2 ton NAPCO kit
In a message dated 1/22/01 8:02:17 PM, Advdesign1@aol.com writes:
<< Jim and all'
The best oil for 216-235s is 10w30 SJ. I'm sorry if my article was not
clear. If you go with 5w30 the volume of viscosity index improvers goes up
which leaves less room in the can for lubricating oil. Without looking in
my
references, there was an issue with excessive VI improvers doing something
under the extreme shear as the oil is rolled between crankshaft and bearing.
If you need more technical info, let me know and I'll look it up. Writing
technical articles for essentially non technical journals is a challenge, as
you don't want to lose the literate as well as the technically illiterate.
Bob ADler
>
> Well I got various messages, the one that I think I will try is switching
to
> 5-30 for the winter. In reading Bob ADlers messages on the Oil subject
and
> his article on Old Truck Mag I was under the impression that I needed to
> stick with straight 30 weight. Also the most important thing was the SJ
on
> the label. Is using 5-30 doing anything that is not desirable to the
motor?
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