Ford also changed the spec back to 5w30 on some of their engines calling for 5w20 to reduce warranty claims years ago. I read that here a few years back, it caused some interesting replies and debate, and some name calling as well.
Will Thinner Oils Damage Your Engine?
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I recall the problem quite clearly.
The oils in question did NOT meet their pour point specs.
GM noted a large number of engine failures in the northern USA and Canada. They ran their own tests and found that several oils did not meet their pour point specs.
Consumer Reports, a major US testing magazine, ran their own tests and failed - among others - one of the Castrol oils for not meeting its pour point specification.
They also tested for shearing by running the oils through diesel injectors.
The specification change came a decade later.
I recall that.
One UOA is not how abnormal wear is normally found. It's the series of UOAs one after the other that show abnormal wear.
Thanks for joining to bring us that. No you don't recall it clearly. Besides there is no "pour point specs", it is a measured value determined through analysis and it is reported as measured. There is no specification for pour point. But there is a specification for the winter rating.
You're new?
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Or maybe the very first UOA was done AFTER the bulk of the damaged had taken place.
My memory is perfect. Unfortunately the material on this is 30-40 years old and so is not on-line and I don't have a scanner to share what I have.
I do see that an article by the late Albert Rossi, who worked for Exxon, shares some the research that was done on the problem:
https://www.jstor.org/stable/44467459?seq=1
The basic problem was paraffin crystallization at low temperatures in the offending motor oils.
The problem went away with the advent of synthetic oils, Group III oils, better pour point depressants, and better QC by the offending refiners.
Which is why they developed 0W oils, improved pour point depressants, and specify lower viscosity oils in cold temperatures.
To alleviate startup wear?Which is why they developed 0W oils, improved pour point depressants, and specify lower viscosity oils in cold temperatures.
If you say so. I read it as a problem where the oil would gel and not flow to the pickup tube and could not be pumped. Of course oil starvation does cause wear.
So glad you joined, we’ll get to know you better as time goes on I’m sure.
It is not black - zero oil pumps - and white - the oil flows like God's grace upon the place beneath.
Viscosity and temperature of a 0W-40 motor oil
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What?
I did find this summary on the February 1987 Consumer Reports article which is not on-line:
Comments on the 1987 Consumer Reports oil test
“... Most oils also passed all the low-temperature tests required in the SAE viscosity grade system, although there were sample-to-sample differences in some products. ...”
“... Four oils -- Kendall Superb 100 10W-40, Kendall GT-1 Turbo 10W-30, Sears Spectrum 5W-30 and Texaco Havoline 5W-30 -- failed low-temperature tests even when more than one sample was evaluated. Consumer Reports' auto engineers suggest you avoid those oils in extremely cold weather. ...”
“... Castrol GTX 10W-40 and 10W-30 and Exxon Uniflo 10W-30 would have been as impressive had all test samples met their viscosity-grade requirements. ...”
Comments on the 1987 Consumer Reports oil test
“... Most oils also passed all the low-temperature tests required in the SAE viscosity grade system, although there were sample-to-sample differences in some products. ...”
“... Four oils -- Kendall Superb 100 10W-40, Kendall GT-1 Turbo 10W-30, Sears Spectrum 5W-30 and Texaco Havoline 5W-30 -- failed low-temperature tests even when more than one sample was evaluated. Consumer Reports' auto engineers suggest you avoid those oils in extremely cold weather. ...”
“... Castrol GTX 10W-40 and 10W-30 and Exxon Uniflo 10W-30 would have been as impressive had all test samples met their viscosity-grade requirements. ...”
With the exception of things like fuel/coolant/water contamination and wear particle analysis to a degree- everything on an OA is anecdotal and needs to be independently validated
Everything on a OA is inferential, not anecdotal.
We note the unusual result, and infer from that certain possible causes.
Welcome Wormwood, glad to have you here. Thanks for sharing so much!
No, that is incorrect on all points.
The OA does not and can not identify a specific source of any detected wear, it cannot quantify any amount directly attributable to and specific component and it cannot even tell when, where or how the wear is incurring.
Also, the OA is purely dependent of the sample, where, when and how it was taken as to whether it is even relevant.
That's just the reality of it. It still takes correlation by other technologies to "infer' anything with any degree of accuracy.
You may read well but its clear you have little to no actual formal training and field experience in the field.
It’s always so entertaining when a new guy shows up with articles and graphs and tries to teach established experts a thing or two.
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