radically diffrent oils - how they suspend soot?
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diffrent oils - radically different appearance of suspended soot?
All right, I'm completely confused. I used Rotella for years, then Rotella Syn in my 2000 PSD. Then when I moved up to Indiana, where it gets marginally cold, I decided to go with Mobil 1 and did that for two winters.
With all these oils, my freshly changed oil would turn fairly dark black within a few hundred miles.
Well, here I go and try Delo again after hearing all good sorts of things about it. You guessed it, it is the color of honey after a 700 mile round trip from Bloomington to Indiana.
Anyone have any ideas what this means? I had heard at one point that the darker the oil got, the more suspended soot the oil was holding, thus doing it's job. Does that ring true to anyone?
The truck seems to like the Delo.
Have any you guys seen anything like this before on your trucks?
With all these oils, my freshly changed oil would turn fairly dark black within a few hundred miles.
Well, here I go and try Delo again after hearing all good sorts of things about it. You guessed it, it is the color of honey after a 700 mile round trip from Bloomington to Indiana.
Anyone have any ideas what this means? I had heard at one point that the darker the oil got, the more suspended soot the oil was holding, thus doing it's job. Does that ring true to anyone?
The truck seems to like the Delo.
Have any you guys seen anything like this before on your trucks?
Last edited by mcjones44us; Jun 5, 2007 at 02:28 AM. Reason: clarity
Fleet Mechanic
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The newer oils are designed to suspend 2x-6x more soot than the older oils. 2002 and later emissions systems dump a considerably larger amount of soot into the oils than pre-emissions engines, largely due to the EGR systems.
-blaine
-blaine
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So my real question is, when you see oil turn quickly dark (assuming you do a proper oil change, not leaving too much old oil in the crankcase), is that a sign that your oil is going it's job well? Would you prefer an oil that turns blacker quicker? Hmmm.
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I'm not sure color change is any reliable indicator of how the oil is performing, or how well it's holding up.
As a case in point, it takes 5000 miles (or so) for the same CJ-4 oil to turn black in my Detroit, and it's a pre-emissions diesel. It took the same amount of time to turn it black when using the CH-4 spec oil (back in 2000).
On the other hand, my college roommate's old GM 6.2 Suburban would turn the oil black virtually instantly. As another data point, my '89 Chevy with the 350 (gas) engine would only slightly discolor the CI-4+ spec oil in a 5000 mile change interval; it was still clear enough to see through, as if it were new.
I think it may be more a function of any given engine than the oil itself. Which may be pointing the way towards oil analysis as the only reliable method of determining when the oil is and is not good.
-blaine
As a case in point, it takes 5000 miles (or so) for the same CJ-4 oil to turn black in my Detroit, and it's a pre-emissions diesel. It took the same amount of time to turn it black when using the CH-4 spec oil (back in 2000).
On the other hand, my college roommate's old GM 6.2 Suburban would turn the oil black virtually instantly. As another data point, my '89 Chevy with the 350 (gas) engine would only slightly discolor the CI-4+ spec oil in a 5000 mile change interval; it was still clear enough to see through, as if it were new.
I think it may be more a function of any given engine than the oil itself. Which may be pointing the way towards oil analysis as the only reliable method of determining when the oil is and is not good.
-blaine
