Originally Posted By: Volvohead
Originally Posted By: JOD
But there is a mountain of evidence out there to support the use of thinner oils
in most applications,
And therein lays the crux of this silly little battle between you (and a couple of others) on one side, and people like Trav who see inside many engines in the field on the other.
Well, Trav, I guess I'll ignore my private advice to you just this once.
Rather than simply make generalized backhanded insults of people like Trav ("this is what they do in Europe" is frankly condescending), why don't you lay out specifically, with actual field and engineering data, studies and evidence, your "
mountain of evidence" supporting the use of thinner oils in
most applications -- including where engine manufacturers have in fact specified a heavier oil.
Citing the statements of a manufacturer specifying a 20 wt oil in an engine is not evidence supporting the use of thinner oils in
most applications. It's evidence supporting its use in THAT application and engine.
Presenting the UOA of a 20wt oil in an engine where the manufacturer recommends that weight is not evidence supporting the use of thinner oils in
most applications. It's evidence supporting the manufacturer's recommendation for THAT application and engine.
These are your contentions. They run directly counter to the manufacturer's express recommendations in some instances, particularly for European engines. I don't fault people like Trav for their strong response, when the field and manufacturer recommendations are contradicting YOU.
Trav is right to ask for credentials. You and several others are speaking as experts might, and present opinions contrary to the engine manufacturers themselves in some instances. In my line of work, it's what we call an adverse expert.
So the evidentiary burden is on you and your fellow advocates.
Thus far, other than parroting a simplistic, mono-dimensional formula on "operational viscosities" using a Widman calculator that ignores the mechanical and other engineering parameters involved in effective lubrication of a modern IC engine's cylinder and bearing systems, nothing meaningful or technically specific has been presented to support the rogue thesis that thinner oils are supported in
most applications.
Oil temperature and pressure and mere operational viscosity is not evidence that thinner oils are supported in
most applications.
Contending that current synthetic 20wt oils are "better" than earlier generation or conventional 30wt oils is not evidence that thinner oils are supported in
most applications.
And insulting and belittling detractors for "not understanding" self-conclusory declarations is not an argument, nor does it improve your intellectual cadence.
Where's the actual evidence of which you speak, advocate?
Were this a court case, you would not survive a motion for summary judgment. I'm not sure you and your colleagues would even survive a Daubert motion.
Saying there's evidence is not the same as presenting it.
Roll out your actual evidence. Take us to the mountain.
Let's see the actual field and lab studies and data supporting the use of thinner oils in
most applications -- even where the manufacturer recommends differently.
Maybe then Trav and some others here might be better convinced.
Sorry, but you're dead wrong. "what they do in Europe" isn't an insult, it's continually given as a rationalization as to why recommendations in the US are sub-optimal. If you feel that's insulting, then I'm not really sure what to say.
As far as the evidence, what exactly do you want? I've already provided links in this thread that deal with hths and engine wear. You could start here:
“Effects of Valve Train Design Evolution on Motor Oil Anti-Wear Requirements”, J.C Bell, paper CEC97-EL02, 5th CEC International Symposium on the Performance
Evaluation of Automotive Fuels and Lubricants, 1997
Engine Friction and Bearing Wear. III. The Role of Elasticity in Bearing Performance”,E.H. Okrent, ASLE Transactions, 7, 1964
“The Viscoelastic Properties of Multigrade Oils and Their Effect on Journal-Bearing Characteristics”, B.P. Williamson, K. Walters, T.W. Bates, R.C. Coy & A.L. Milton, J.
Non-Newtonian Fluid Mech., 73, 1997
"Piston Ring Oil Film Thickness - The Effect of Viscosity”, S.L. Moore, SAE 850439
“Influence of Piston Ring Gaps on Lubricating Oil Flow into the Combustion Chamber”,K. Nakashima, S. Ishihara & K. Urano, SAE 952546
These are all published scientific papers which deal with various facets of how viscosity relates to engine wear. The source document is
here , and there are some citations from those texts, which accompanying charts, which detail the relationship between wear and viscosity.
Of course, much of this is centered around theory, modeling and lab tests. As mentioned in the source document, the proof is ultimately in long-term field testing. Well, multiviscosity 20W oils have been in wide use now for a long enough time that cars using them are into the hundreds of thousands of miles, and I haven't heard of a disproportionate number of lubrication-related failures on vehicles using 20W oils. While single UOA's certainly don't tell you much about engine wear, a compilation of all of the UOA's available may offer some insight. Someone on here's already done that, and 20W oils showed less wear. While not proof that they're better, given all of the variables involved, it certainly demonstrates that they protect adequately.
Simple question: where are the instances of specified oils not adequately protecting an engine? I've seen questions/anecdotes about one model of V-6 Honda. Anything else?
