Caddy DTS 5300 miles on mobil one synthetic

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excuse me, could not figure out how to make this a nice picture!
2008 cadillac DTS, northstar v8, 51,000 miles, did 5300 miles on mobil one synthetic. blackstone labs used.
aluminum 4
iron 7
molybdenum 68
boron 39
silicon 5
calcium 1136
magnesium 666
phosphorus 689
zinc 740
sus viscosity 57
cST viscosity 9.6
fuel less than 0.5%
water zero
insolubles just a trace
TBN 2.2
now my dumb questions
they gave this a good review, and said to try 7000 miles next time.
1. what does molybdenum represent?
2.what do you experts think of a TBN of 2.2?
3. how long would you go before my next oil change?
THANK YOU!!
Bob
smile.gif
 
Molybdenum is an anti-wear oil additive. Some oils have lots, some have little, it is isn't a wear metal like aluminum or iron, so it's really of limited interest.

This is actually a really good used oil analysis. Wear metals are low, silicon (typically a contaminant entering because of a compromised air filter) is low, fuel and water are fine.

If this oil analysis was done by Balckstone, they'll typically suggest changing oil when the TBN gets to 1.0. Because TBN depletion isn't linear, you may have a bit of life left in this oil. On the other hand, Mobil1 starts off with a 100C cSt of 11.0 and your sample was at 9.6. So your 5w/30 sheared down quite a bit and is approaching 5w/20 territory.

So, under these driving conditions, it looks like a 5-6,000 mile OCI makes sense. I suspect your car has an intelligent oil life monitor which allows you a see "% oil life remaining". If you recall what that was when the oil was changed, it's not a bad target to use for future oil changes. This sample probably saw cold weather use and a summer fill may last a bit longer; the intelligent oil life monitor should take this into consideration as well as changes in driving patterns.
 
Originally Posted By: Danh
Molybdenum is an anti-wear oil additive. Some oils have lots, some have little, it is isn't a wear metal like aluminum or iron, so it's really of limited interest.

This is actually a really good used oil analysis. Wear metals are low, silicon (typically a contaminant entering because of a compromised air filter) is low, fuel and water are fine.

If this oil analysis was done by Balckstone, they'll typically suggest changing oil when the TBN gets to 1.0. Because TBN depletion isn't linear, you may have a bit of life left in this oil. On the other hand, Mobil1 starts off with a 100C cSt of 11.0 and your sample was at 9.6. So your 5w/30 sheared down quite a bit and is approaching 5w/20 territory.

So, under these driving conditions, it looks like a 5-6,000 mile OCI makes sense. I suspect your car has an intelligent oil life monitor which allows you a see "% oil life remaining". If you recall what that was when the oil was changed, it's not a bad target to use for future oil changes. This sample probably saw cold weather use and a summer fill may last a bit longer; the intelligent oil life monitor should take this into consideration as well as changes in driving patterns.



Molybdenum is not an anti-wear anything. Its a friction modifier,big difference and not always interchangeable.
 
Originally Posted By: Clevy


Molybdenum is not an anti-wear anything. Its a friction modifier,big difference and not always interchangeable.


If something has less friction due to adding a friction modifier, wouldn't it be considered an anti-wear additive? Isn't that the whole point of adding friction modifiers in engine oil is to reduce wear? Transmission oils and gear lubes are completely different though.
 
Originally Posted By: Clevy
Originally Posted By: Danh
Molybdenum is an anti-wear oil additive. Some oils have lots, some have little, it is isn't a wear metal like aluminum or iron, so it's really of limited interest.

This is actually a really good used oil analysis. Wear metals are low, silicon (typically a contaminant entering because of a compromised air filter) is low, fuel and water are fine.

If this oil analysis was done by Balckstone, they'll typically suggest changing oil when the TBN gets to 1.0. Because TBN depletion isn't linear, you may have a bit of life left in this oil. On the other hand, Mobil1 starts off with a 100C cSt of 11.0 and your sample was at 9.6. So your 5w/30 sheared down quite a bit and is approaching 5w/20 territory.

So, under these driving conditions, it looks like a 5-6,000 mile OCI makes sense. I suspect your car has an intelligent oil life monitor which allows you a see "% oil life remaining". If you recall what that was when the oil was changed, it's not a bad target to use for future oil changes. This sample probably saw cold weather use and a summer fill may last a bit longer; the intelligent oil life monitor should take this into consideration as well as changes in driving patterns.



Molybdenum is not an anti-wear anything. Its a friction modifier,big difference and not always interchangeable.


Well, OK, maybe. But lower friction usually, if not always, goes hand-in -glove with lower wear. But the distinction is tomato-tomahto in the context of the OP's question.

And even here on BITOG, the explanation of molybdenum says "Instead of metal rubbing against metal you have Moly platelets moving across one another protecting and lubricating the metal engine parts."
 
Given that a TBN of 1 is low, I think you're probably as close to the sweet spot as you can get without pushing it.
 
Originally Posted By: SVTCobra
If something has less friction due to adding a friction modifier, wouldn't it be considered an anti-wear additive? Isn't that the whole point of adding friction modifiers in engine oil is to reduce wear?

Not exactly. There are plenty of resources on the board here about it. The quick version is that a friction modifier in motor oil is generally to improve fuel economy. As you mention, that's not the same issue as it is in transmissions.

Moly can be more of a friction modifier or more of an anti-wear compound, depending upon the concentration. From what I understand, if the amounts are very high, it's more of an AW compound. There are probably temperature related effects, too. Someone like Mola would do a much, much better job of explaining it than I would.
 
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