11 Mercedes ML350 Bluetec 3.0L M1 ESP 5W-40

[Quattro Pete]

FYI, according to the VOA that we have, M1 ESP 5w-40 has a starting TBN of 5.5, which is not surprising since it's a low SAPS oil...

http://www.bobistheoilguy.com/forums/ubb...-Oi#Post2047885

 

[m37charlie]

Wow! That's significantly worse than my 09 BMW X5 35d.
I'm using Delvac 1 LE 5W30 and getting better results.
If we could get Castrol Vecton Long Drain LS 10W40 or 5W30 I'd also recommend that. It is also an ACEA E6 oil with P
Charlie

 

[Fraser434]

Looks like that low saps oil is offering great protection.....

Also keep in mind TBN goes up/ lubrication goes down, balance of additives.The combustion by product acids are mainly from sulfur. ULSD doesn't need as much TBN; hence low saps, C3, 229.51 oils will have a lower TBN.

Overall you're going to see TBN go down across the board for HDEO looking for better wear numbers.

 

[m37charlie]

Originally Posted By: Fraser434
Looks like that low saps oil is offering great protection.....

Also keep in mind TBN goes up/ lubrication goes down, balance of additives.The combustion by product acids are mainly from sulfur. ULSD doesn't need as much TBN; hence low saps, C3, 229.51 oils will have a lower TBN.

Overall you're going to see TBN go down across the board for HDEO looking for better wear numbers.


Not true IMHO. Why does my TBN drop from 10 to 3.5 in 11000 mi burning ULSD, in the BMW? The reason is EGR. With EGR the engine inhales its' own NOx which is very acidic - forms nitrous and nitric acids in combination with water vapor in the exhaust.
OTOH my Unimog sans EGR has TBN drop only from 16 to 12.4 in 17500 mi.

Charlie

 

[abycat]

aluminum is not the lowest either.

 

[Fraser434]

Originally Posted By: m37charlie
Originally Posted By: Fraser434
Looks like that low saps oil is offering great protection.....

Also keep in mind TBN goes up/ lubrication goes down, balance of additives.The combustion by product acids are mainly from sulfur. ULSD doesn't need as much TBN; hence low saps, C3, 229.51 oils will have a lower TBN.

Overall you're going to see TBN go down across the board for HDEO looking for better wear numbers.


Not true IMHO. Why does my TBN drop from 10 to 3.5 in 11000 mi burning ULSD, in the BMW? The reason is EGR. With EGR the engine inhales its' own NOx which is very acidic - forms nitrous and nitric acids in combination with water vapor in the exhaust.
OTOH my Unimog sans EGR has TBN drop only from 16 to 12.4 in 17500 mi.

Charlie


The TBN would would be affected more with higher sulfur in the exhaust which would go through the EGR.
It's more than just NOx that goes through the EGR HC, CO,PM, SO2,SO3 etc. The purpose of the EGR is actually to lower NOx levels.

Point is you're not going to see 10+ TBN numbers with newer oils , and don't consider them "weak" because they don't measure 12 TBN. TBN isn't lubrication, it's detergents.

 

[m37charlie]

True, detergents are not DIRECTLY anti-wear, but un-neutralized acidity causes wear and corrosion. Look at emission requirements with EGR alone from 1998 to 2006 (down only 50%) vs down another 97.5% with adding SCR/urea. The point is that when the exhaust has not yet been treated there are still significant amounts of acid forming NOx. And nitric acid is just as strong an acid as sulfuric.

Charlie

 

[RLGDiesel]

OP...could you describe your sampling method during the oil change? Perhaps pulling a sample too early or late in the process or contaminating it with a dirty drain pan might lead to higher wear numbers/viscosity. You seem pretty meticulous though...so not a really high likelihood.

Good luck...the 642 is a good engine and apart from a few oil leaks and intake swirl motor problems , I have yet to hear of any major oil consumption or failures. I know they are prone to higher fuel dilution due to the exhaust clean-up. You might not be far off the mark with the break in theory though.