NOACK questions

[Stelth]

In perusing various PDS's, I'm seeing a lot of variation in NOACK volatilities. For instance, Peak 5w30 shows 14.5, and their 10w30 is 15.2. Valvoline NexGen shows 5w30 @ 14.4 and 10w30 @ 11.3. Pennzoil Conventional 10w30 is 13.7 and 5w30 is 14.5.

First question, how much difference does it make on a day-to-day basis if, for instance, you change from a 10w30 with a 15.2 NOACK to one with 11.3?

Second question, the 5w30's all have similar numbers, but the 10w30's vary widely. Any insights on why that is?

 

[tinmanSC]

You sure it was 15.2? A NOACK of >15 doesn't meet API spec. for PCMO.

 

[CATERHAM]

NOACK is not important other than as an indicator of base oil quality.

In typical street use applications with low oil temp's, even the maximum NOACK percentage of 15% doesn't translate into noticeably higher oil consumption vs a lower NOACK oil.

 

[ericthepig]

Originally Posted By: CATERHAM
NOACK is not important other than as an indicator of base oil quality.

In typical street use applications with low oil temp's, even the maximum NOACK percentage of 15% doesn't translate into noticeably higher oil consumption vs a lower NOACK oil.


True. Plenty of anecdotal data on BITOG. Cheap dinos, expensive synths, etc going 7+k and "didn't burn a drop". If NOACK mattered, you'd see consumption corresponding to the NOACK values. But it doesn't happen.

 

[addyguy]

NOAK mattered a lot more, or played a bigger role, in the 1970's with the use of all-group I base oils.

NOAK was easily over 25% for most oils, so most oil consumption was just evaporation. When synthetic basestocks came along, that's when you started to see things change, and people notice how much less oil loss there was with them., and started to want that in conventional oils.

Now, all oils capped at 15% to meet spec, and everything, even syns, howering around 10-15% for NOAK, there isn't really a difference between oils in this area anymore, and no real need to pay attention to this value.

 

[Stelth]

Originally Posted By: tinmanSC
You sure it was 15.2? A NOACK of >15 doesn't meet API spec. for PCMO.


I'm pretty sure it's correct. The PQIA website shows several SM oils with over 15% NOACK - Wolf's Head with 15.4, CarQuest with 15.2, Gulf with 15.1 (all 5w30's), and more. These are all SM oils. I feel better having an oil with a NOACK below 15.

 

[CATERHAM]

Since all these batteries round down to 15% they meet the API spec'.

 

[Stelth]

Originally Posted By: CATERHAM
Since all these batteries round down to 15% they meet the API spec'.


Yeah, that's pretty much what the PQIA site said. I'd still rather go with something under 15.

 

[Unleashedbeast]

Originally Posted By: addyguy
Now, all oils capped at 15% to meet spec, and everything, even syns, howering around 10-15% for NOAK, there isn't really a difference between oils in this area anymore, and no real need to pay attention to this value.


True synthetic formulations will have very low NOACK % ranging from 5.x% up to 8.x%

 

[SIXSPEED]

Originally Posted By: Stelth
Originally Posted By: CATERHAM
Since all these batteries round down to 15% they meet the API spec'.


Yeah, that's pretty much what the PQIA site said. I'd still rather go with something under 15.

Motor oils that comply with ACEA A3/B3/B4 and A5/B5 European oil standards must demonstrate NOACK <= 13%.