Originally Posted By: coolbird101
What does a noack of 18 vs 15 or even lower like Sopus products mean to the engine? does this mean more wear? A dirty engine? Sooner top offs? It's been mentioned on here that the TEOST is more indicative of deposits left behind, with that being said, what does this all mean? other than a possible quality control issue.
I suspect this has nothing to do with the fact that it's recycled.
Noack measures volatility, and under the conditions of the test primarily the amount of light ends. Variations in Noack volatility may affect oil consumption and deposits, but not to a great degree. Your engine will not self destruct.
The Noack result is often a good indicator of the quality of the base oils used. In my opinion, ILSAC ratcheted down the Noack specification to force formulators to use more higher quality base oils, more so then to improve volatility related engine performance. It was an easy way to push oils into Group II and III, which increased demand for these better base oils, and therefore supply. The result is that virtually all conventional oils today are now using higher quality base oils, which makes engine builders happy.
Tom NJ