Thread: Lubricity Study
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Old 04-02-2010, 02:05 PM   #59
Scraping Paint
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RE: Lubricity Study

Yeah, all one has to do is go the local auto parts store, particularly the chain stores like Shucks (or whatever it's called now) and look at all the additives that say they do this, that, or the other thing to realize that most of them are probably the same ingredients with different packaging and claims. And what is it that FF says he's heard Mystery Oil is? Diesel fuel with red dye and an aromatic to make it smell different?

But while I've got your attention Mike, here's an unlreated mystery I've wondered about for decades that perhaps you can explain for me since you're in the business. When I bought my 1973 Land Rover new I obviously wanted to do what was best for the engine. At that time, STP oil treatment was promoting itself heavily so I tried it. Put in a can per the directions (with the engine running). Then I drove home. Immediately, whenever I started out under engine load from a stoplight or whatever, the engine would knock. Badly. So on the way home I stopped at an auto store and bought some new oil and changed the oil when I got home. No more knocking. But the claims for STP were so compelling I decided to try it one more time.

Same exact deal. Put the STP in and immediately the engine would knock under load. Changed the oil when I got home, no more knocking. That ended my experiment with STP forever and I've run that engine (and all our other vehicle engines) on un-altered Castrol 20-50 ever since.

But try as I might, I have never been able to come up with a plausible explanation of why the addition of STP to the lube oil made the engine knock. Any ideas?
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