Originally Posted By: Oil Changer
I didn't change anything; I was being generous by adding dexos. Name one oil that meets GM's new vehicle warranty requirements that doesn't have the required Noack value. I'll help, you won't find one. Furthermore, we agree more than you will admit. The dexos standard is tough. That's why even the best oils still have double-digit values. Much like the PAO/POE craze of the past where people thought all or more made the oil "the best", having a lesser Noack value does not necessarily make it a better oil. As always, it's the complete package.
The issue I have is this ridiculous obsession with people thinking that an oil with a Noack higher than 5% is somehow no good. This craze is no different than searching for an oil that has all PAO for base stock. Fool's errand. There is not one oil that is name brand, SN, or dexos that will not fully protect 99.9% of the vehicles on the road.
Other responses already addressed your second paragraph.
Edited to add: Are there any oils that are dexos licensed and NOT SN? I don't think so.
Originally Posted By: NMBurb02
Wait a minute. You're changing your answer from any SN spec oil to SN/dexos spec oil. SN has a max allowable Noack of 15% whereas dexos specs a max of 13%. So any GM engine requiring a dexos spec oil will not be fine with any SN oils (namely those with Noacks of 13.1% to 15%). And while you may feel Noack is not all that important of a spec, GM seems to think that it is.
And hot running engines are not the only ones that reach oil temps of 250C (the Noack performance test temp), as I believe (is that an acceptable term?) I have read on BITOG that oils regularly reach that temp in certain parts of normally functioning engines.
Yes, you did change. First, you said SN would do fine in 99.9% of cars and you wanted someone to point out any vehicles that require Noack less than 15%. In your next post, you lumped SN and dexos into the same category, which they are not. One of the differences between SN and dexos is Noack, so unless GM vehicles requiring dexos oils make up less than 0.1% of vehicles on the road, then your original assertion that 99.9% of vehicles are fine with SN (and therefore Noack of up to 15%) is wrong. And FetchFar pointed out that MN 229.5 has an even lower Noack requirement of 10%. So there are a lot of vehicles for which the OEMs feel a Noack of 15% is too high.
And I doubt there are any dexos oils that do not meet SN, but there definitely are SN oils that do not meet dexos specs, which was my point.