STP 4-cyl vs. Regular

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May 22, 2006
N. Calif - State of Jefferson
I see on the STP MSDS data sheets (from the Clorox company) show that their regular label of STP Oil Treatment vs. the STP 4-cylinder Oil Treatment shows zinc called out (Zinc Dialkyl Dithiophosphate) whereas the regular is not. Would this indicate that their brand specific for 4 cylinder models, as indicated, is better as far as Zinc is concerned....versus just using their regular brand of oil treatment? weblink: GL
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There is a VOA on the 4-cyl treatment. It has good levels of zddp, but I don't recall off hand. If you can't find the VOA let me know, but I think it's the thread that is a whole bunch of VOAs (first thread in VOA forum, by Stinky Peterson--RIP), was Butler Cat Labs in Bismark ND few years back. As I recall from talking to the manufacturer, the 4 cyl has same or more zddp, but half as thick and that alone is good reason to go with the 4-cyl stuff. But if all you want is zddp I would get the Redline stuff, one ounce per quart gives about 575 boost in zddp, so you could get along fine at 2-3 oz per crankcase full. And being Redline you know it's good stuff. With STP I suspect you get a lot of funky VII you don't really need. The Redline break in additive is about 10.5 cSt like a 30 wt oil.
Just curious, did STP change the formula for the Blue Bottle? I have an older plastic bottle of it, and it says it contains ZDDP, then something about detergents and other AW adds. It is some thick stuff, we used it for a cutting oil for neck turning while reloading ammo. It worked well for that. AD
Ohhhhhhhhh Yeah! The Gold Bottle: STP 6000 Mile Oil Extender! Yeah, almost forgot about that stuff. I picked up about 9 pints about 4 or 5 years ago on clearance. Was not thick. Never VOA'd but back label says has zddp (I have an empty in the cellar I just dug up). Label copyright is 2000. Sad they get rid of good stuff like that.
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