Originally Posted By: CATERHAM
I agree from a practical point of view Noack has zero importance.
That's probably over-doing it
Quote:
It's one reason some people think that a 10W-30 synthetic is not an obsolete product because it has a lower Noack vs a 5W-30 of the same brand.
Aw yea!
and less VIM/ varnishing potential and a touch higher HTHSV; in a climate where even the 10W rating will never be challenged, what's not to love about that?!
Quote:
No at the top of my list are a low KV40 value for it's HTHSV, a high AW additive level and reasonable shear stability.
And that is perfectly reasonable. There are times when that's my own priority also, mainly because I still like to micro-optimize for operating conditions and climate and live in a frozen wasteland.
To those that like to revel in the one size fits all-ability of new oil technology, 'set-it-and-forget-it', there's nothing wrong with it, I done it. The operating margins of the ECO oils is wide (on the cold side)- not optimal for heavier duty, but very much acceptable for most motoring, thanks to supporting industry changes.
Originally Posted By: Shannow
Another issue is LSPI, and the presence of oils in the hot compressed air in and around the ring belts (the location at which NOACK is modeled).
http://energy.gov/sites/prod/files/2014/03/f8/deer11_alger.pdf
Have read a couple of articles that say NOACK is a poor indicator of LSPI, and the linked article is about oil reactivity, but if the oil's not there, it doesn't matter if it's reactive...they need a test that does double duty...like NOACK measures one thing, but the stability of the phosphorus compounds partly dictates the phosphorus carry.
How about a consumption test, which measures an oil's predisposition to being consumed
Nice paper, very interesting to the tuning mind.
Notable sidenote on how ester base oils have the lowest CN, ANs in the middle while PAO has the highest. I can see yet another reason why a blender like Redline sticks with esters.