Originally Posted By: Shannow
Originally Posted By: DrRoughneck
According to
these measurements , the film strength of Mobil 1 5W30 advanced synthetic is 117,799 psi.
The study measured the film strength of 174 different oils and 5W30 Mobil 1 came on top.From what I understand film strength is measured by squeezing 2 ball bearings together with a film of oil in between. The force with which the balls are squeezed is gradually increased until current passes through, meaning there is metal-to-metal contact.
How do you know that about the Rat's secret test procedure ?
How does he calculate the psi to 6 significant figures, when the ASTM test for greases (which is what these tests are for) only works in 200lb increments, and only allows you to claim the last load that it DIDN'T fail at ?
What is his definition of "film strength", and what does it have to do with hydrodynamic film thickness in engines ?
Is steel on steel representative of mixed metals like bearings ?
He claims that the test has nothing to do with any part in an engine, but that his results tell you everything that you need to know about oil and engine wear.
Why does he completely discount HTHS in his ultimate wear testing, when all OEMS and certifying agencies have it as one of the key parameters in their certifications ?
Given that he's been around a while, why do the oil companies and OEMS stick to expensive to run engine tests, when he could save them 99c in their dollar of testing ?
He claims that his stove top smoke point is analogous and superior to the formal NOACK procedure...again, if this was the case, why did industry end up so far off the mark ?
If I had a (secret) Rat machine that I didn't want to wear out, I'd use what his test machines shows the lowest wear in that machine.
Been into this extensively on other threads on Bitog and elsewhere... 540 RAT and I have corresponded on a number of occasions and he has tested oils that I was interested in. I will not say his testing is bogus. Any testing that tells us anything has some value
The biggest issue he was, and is testing for, is for those of us building flat tappet cam engines. And that was what RAT was trying to help solve - cam and lifter failures.... Mostly for his roundy round race buddies and customers. He does not sell oils or additives, but diagnostic services...
His test do not really apply to most aspects of an internal engine, but seem to relate to cams and lifters (steel on steel) fairly well. And for that I look for a good oil that interests me, is well received here on Bitog, AND is in the top third of RAT's list. I feel confident that any of his well rated oils are, in fact, just that - well made lubricants
I do not see a downside to considering his information. If you are an RP fan it didn't do to well, well you got some pondering to do... Me, I'm a Chevron, QSUD, Maxlife, VR-1, Delvac guy and I don't see anywhere that my choices are bad for the applications I'm applying them in. Either in discussion here on Bitog, or in communication with RAT
Take it with a grain of salt and use the info as
one input in your decision making process ...
Don't get all caught up in his calculator read-out descriptions. He's trying to get relative rankings, so he takes the math as far as it need to go to separate the various oils. His numbers are not valid for actual internal engine loads on components (which is why he says they do not correspond to actual engine situations...).
