On Thu, 9 Nov 2000 17:20:50 -0600, David K Yeung <dkyeung@juno.com> wrote:
>here's one for the folks in-the-know about lubricants.
>I saw an ad in my C&D for STPs oil extender. Is this stuff basically the
>additive pack that all motor oil manufacturers include but may wear out
>before the oil change interval is up? The real question is should these
>oil extenders be used? is there one that is economically reasonable to
>use? or is the opinion that oil is cheap enough to change more frequently
>if needed; especially since we're all ecologically responsible and
>recycle our used motor oil.
Don't bother. The STP stuff is *theoretically* the basic additive package
that's in new oil. There's only one great big huge problem, though -- what
do you do with all the chemical contaminants in the oil, not to mention the
dirt and grime not caught by the filter, and oxidation of the base
lubricants (which can lead to sludging and loss of lubricating ability)?
With this stuff, you keep recycling it through your engine.
With fresh oil and a fresh filter, you flush out most of the nasty stuff
when the oil drains out of the sump -- the combustion byproducts (water,
acids, light hydrocarbons, heavy hydrocarbons, soot, and other things that
can do Nasty Things internally), trace amounts of engine metals (bearings,
crank, block, cam, valvetrain, etc.), and the old, tired, oxidized oil, and
you replace it with fresh oil that has a fresh batch of the various
additives (detergents, dry-film lubes, anti-oxidants, anti-foaming agents,
etc.) your engine needs, plus a shiny new filter with fresh media just
hungry to intercept all those harmful particles before they score your
crank journals and wipe your cam lobes.
One of these days, I'll freshen my treatise on oil additives and "engine
treatments" and post it up to the team.net FTP site. It documents why I'm
against using any of the various snake oils available, and why you should
be, too. I've been thinking about shopping it to a paying publication and
may do that first, though.
Jim Crider
PS: DCX's mail system blocks Juno, Yahoo!, and Hotmail, so just send
replies to autojim@delphi.com and I'll read it at home.
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