Lubrizol - Wear & GF4

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Oct 11, 2002
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Colorado Springs
According to this, 800 ppm phosphorous is about the limiting factor to engine wear. I'm satisfied that GF-5 does not limit phosphorous beyond GF-4, at 800 ppm. Engines with roller valvetrains are much less succeptable to these lack of zinc/phosphorous concerns. And even at that, a modern factory DOHC solid lifter valvetrain hardly puts any additional stress on the valvetrain compared to a rollervalvetrain. Toyota, the god of the automotive world, still primarily uses a solid lifter DOHC valvetrain.
 
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Aug 5, 2008
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Aridzona
This is a very sloppy bit of reporting. The first graph begs a huge question. The 500ppm sample held up very well for the first 80 hours, then fell to pieces. At 800ppm, wear took twice as long to get going, but then accelerated at a rate nearly identical to the 500ppm sample. Can I assume the ZdP is being depleted during the test? And if 800ppm is good, wouldn't 1200ppm be better? (I understand that very high concentrations are sub-optimal.) The paper ignores this point, and leaps to the seemingly forgone conclusion that '800ppm ought to be enough for anybody.' \:\(
 
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Jul 27, 2006
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Southwest Virginia
 Originally Posted By: Geonerd
This is a very sloppy bit of reporting. The first graph begs a huge question. The 500ppm sample held up very well for the first 80 hours, then fell to pieces. At 800ppm, wear took twice as long to get going, but then accelerated at a rate nearly identical to the 500ppm sample. Can I assume the ZdP is being depleted during the test? And if 800ppm is good, wouldn't 1200ppm be better? (I understand that very high concentrations are sub-optimal.) The paper ignores this point, and leaps to the seemingly forgone conclusion that '800ppm ought to be enough for anybody.' \:\(
+1 Spot on. \:\!
 
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Aug 12, 2005
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NW Ohio
The linked story is now gone. Wanted to look at it! I wonder if it's being revised? Perhaps based on critical review?
 
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Feb 1, 2003
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RI
Its still there. Just have to follow the link. Click back to newscenter to find all the articles. And reclick on the link for this article. They need to test with different additive substitutes. Testing with GF-2 oils is a joke. Why didn't they just use some GF4 oils with different additive levels??? Add some moly or boron to the test. Maybe use some full synthetic base stocks too. If its a poorly blended oil, I'll take it with extra zdp.
 
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