Motorcraft Oils

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RAK

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The Petroleum Quality Institute of America lists both MC's 5W20 and 5W30 volatility (15.2%) as near the maximum
limit. Can anyone please explain how volatility comes into play and should I be concerned since I use both MC
viscosities in my vehicles? Thanks in advance!
 
NOACK is a measurement of volatility, or how much of the oil "burns off" with repeated heating.
This can cause the appearance of oil loss as well as thickening of oil during use.
I have also read it can increase the amount of sludge buildup in an engine.

I know Motorcraft oil has always been seen as a good oil, not sure what the deal is if the NOACK is ~15. That is the high limit of the SM rating.
 
"Volatility, mass % loss, 1 hr, @ 250ºC (ASTM D5800)" Somebody on here said very few engines run oil at that temp for a hour, so probably not to worry. My 2010 Ford Ranger 2.3 has 71K on it, previous owners had used Motorcraft 5W20 only. When you look into the oil fill, it looks like brand new engine.
 
When oil volatises it let behind the dirt it was dispersed on it, leaving varnish and sludge precursors.
When you shut the engine down, the cc heat, makes the engine head to cook that guey stuff.
 
Last edited:
Originally Posted By: OPR4H
When oil volatises it let behind the dirt it was dispersed on it, leaving varnish and sludge precursors.
When you shut the engine down, the cc heat, makes the engine head to cook that guey stuff.


Hey can you go back and comment on that other thread where you said that silicon deposits are left behind?
 
250C is 482F, so you're in trouble if the oil in your sump is sitting at that temp!
The kicker is that oil can be exposed to much higher temperatures as it flows by hot spots in the engine, and especially high ones for a turbo engine that can have parts rotating at X0,000 RPM. Of course, the exposure times are going to be brief as long as the oil is flowing properly.
I doubt these temps are going to be super extreme in a Ford V8, and even a good synth like M1 5W30 has a NOACK loss of 10%...not drastically lower than the MC oils you are talking about. You have to look at specialty oils like Redline, Amsoil SS, and M1 ESP to get NOACKs down towards the 5% range in the 5W30 oils.
 
I too am curious of the real world impact that NOACK has on engines. I currently run MileSyn 5w30 with a value of 14.5. I am only running 5k intervals due to me having a 5.4 3v engine. I would suspect that at this interval, there is no 'visible' difference between a 14.5 and lets say a 9?
 
While I understand the importance of NOACK values being low, I often wonder what the 'real-world' impact is, for most vehicles.

I say this because, even though I've used plenty of oils with a NOACK in the 12+ range in my Fusion, I never notice any measurable drop in oil levels after a 7500 mile OCI. If NOACK is 12%, shouldn't that mean that if it really had an impact, I'd expect to see my oil level drop by some noticeable portion of 12% after 7500 miles?

I've run lots of 7500 mile oil changes, and I've never seen it drop by even a tiny amount.


... I think Virtus Probi got it right - The actual amount of time the oil in most engines actually spends anywhere near that 250C temperature is actually quite low. I'd say it spends most of its time at or below the average coolant temperature, which in my Fusion is about 200-202F... less than half of the 250C figure used in NOACK tests.
 
Many thanks, guys, for your feedback and input! I think I
have a better handle now on what volatility is and how it works.
RAK
 
Originally Posted By: SirTanon
While I understand the importance of NOACK values being low, I often wonder what the 'real-world' impact is, for most vehicles.

Depends on the vehicle and the conditions. Some run really hot.

What might really help is an coolant heat exchange oil cooler. My last two cars both had one on the oil filter mount. I understand that it both helps with warming up and of course keeps the engine from getting much hotter than the coolant temperature.
 
Originally Posted By: kschachn
Originally Posted By: OPR4H
When oil volatises it let behind the dirt it was dispersed on it, leaving varnish and sludge precursors.
When you shut the engine down, the cc heat, makes the engine head to cook that guey stuff.


Hey can you go back and comment on that other thread where you said that silicon deposits are left behind?


Ther you go

Originally Posted By: OPR4H
Originally Posted By: kschachn
Originally Posted By: OPR4H
If that head takes more time to cool off than the cleaner one, that may contribute to varnish. Rear banks can have a worst scenary in that regard.

This or a restricted lubrication by blockage (specially silicon on galleys) getting less cooling effect from the oil.


Silicon accumulates on galleys? How does that happen? Where is the silicon coming from?


Evidently silicon as gasket material, if the excess dislodges, obviously goes to galleys.
 
Originally Posted By: OPR4H
Ther you go


Yeah I saw it earlier. It's not silicon, it's silicone RTV and you're implying pieces break off and lodge in galleys.
 
CriticalMass - that's where I am - paid $50k for a CUV with a twisty dual TDI engine and I don't even trust what Ford is peddling for oil - it is a motor known for cutting viscosity or CBU ... I'd prefer Ford only covers mine 60k and I want 2x that or more ... I'm sticking with 5k OCI too ...
 
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