Rotella T Synthetic Oil
09-01-2005, 01:23 AM
#26
Super Member
Join Date: May 2003
Location: Boise, ID, USA
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300D, 500E, E420
Good stuff here. A few comments (may or may not be 100% accurate - take with a grain of salt.)
1) The factory oil filter on MB diesels won't filter soot - period. Mercedes expects the oil to suspend the soot. You need to change the oil before it reaches the limit of soot suspension, which is approximately 2% on all the older M-1 varieties, but over 4% for Delvac-1. (I'm not sure about the new M-1 EP's but I'm assuming they are 2% or so.) I've been told, without any confirmation, that Mercedes recommends the oil be changed when soot percentage reaches 2% regardless of what the oil can suspend (meaning you shouldn't go to 4% just because D-1 theoretically handle it.) My older OM603 engine is around 1% soot at 10kmi which works fine for me.
2) Bypass filters are a whoooooole separate topic. They do keep the oil near virginal at all times, assuming you change the toilet paper (no joke) cartridge every 2-2.5kmi on schedule. I'm personally not a big fan of these due to the frequency of TP change, and the fact you need to add a quart of oil with every TP change. This kills any cost savings over plain ol' extended OCI's in the 10-15kmi range (assuming UOA allows that in the first place.) Also, on most newer cars, finding space to install the bypass filtration system can be a pain. On a late 70's or early 80's Benz, there's room for a whole 'nother engine under the hood, so locating a spot to mount an extra canister is not a problem. But on a new CDI? Good luck... and the dealer/warranty question is not to be taken lightly either.
Maybe add the setup after the warranty expires if MBUSA gives you any flak.
3) On the older (non-CDI) Mercedes diesels, the filter cartridges were allegedly 3x-4x oversize for the 'normal' 5-6kmi change interval, and are generally considered OK for extended drains to 10-20k or so assuming UOA numbers are good. I'm not confident of the accuracy of that assumption and I have NO idea what the new CDI filtration is like. I have been changing my filter with the oil at 10k, not changing the filter every 5k (I used to do that a long time ago but then was told the 3x-4x thing so I stopped. Hmmm.)
4) I have a PDF of my current OM603 oil analysis at this link. The first page shows a single 10k interval with Delvac-1. I have gone through 2 more 10k D-1 intervals since then and am about to complete a third... I need to update the PDF, huh. (Ooops.) I should have a good trend to display now. Soot averages 1% (approx) at 10kmi.
Finally... anyone see the specs on the new 2006 E420 CDI twin-turbo V8? Here's a thread with a link to some photos & techie details. Huge power, crazy fast... me want... probably not imported to the USA though.
1) The factory oil filter on MB diesels won't filter soot - period. Mercedes expects the oil to suspend the soot. You need to change the oil before it reaches the limit of soot suspension, which is approximately 2% on all the older M-1 varieties, but over 4% for Delvac-1. (I'm not sure about the new M-1 EP's but I'm assuming they are 2% or so.) I've been told, without any confirmation, that Mercedes recommends the oil be changed when soot percentage reaches 2% regardless of what the oil can suspend (meaning you shouldn't go to 4% just because D-1 theoretically handle it.) My older OM603 engine is around 1% soot at 10kmi which works fine for me.
2) Bypass filters are a whoooooole separate topic. They do keep the oil near virginal at all times, assuming you change the toilet paper (no joke) cartridge every 2-2.5kmi on schedule. I'm personally not a big fan of these due to the frequency of TP change, and the fact you need to add a quart of oil with every TP change. This kills any cost savings over plain ol' extended OCI's in the 10-15kmi range (assuming UOA allows that in the first place.) Also, on most newer cars, finding space to install the bypass filtration system can be a pain. On a late 70's or early 80's Benz, there's room for a whole 'nother engine under the hood, so locating a spot to mount an extra canister is not a problem. But on a new CDI? Good luck... and the dealer/warranty question is not to be taken lightly either.
Maybe add the setup after the warranty expires if MBUSA gives you any flak.3) On the older (non-CDI) Mercedes diesels, the filter cartridges were allegedly 3x-4x oversize for the 'normal' 5-6kmi change interval, and are generally considered OK for extended drains to 10-20k or so assuming UOA numbers are good. I'm not confident of the accuracy of that assumption and I have NO idea what the new CDI filtration is like. I have been changing my filter with the oil at 10k, not changing the filter every 5k (I used to do that a long time ago but then was told the 3x-4x thing so I stopped. Hmmm.)
4) I have a PDF of my current OM603 oil analysis at this link. The first page shows a single 10k interval with Delvac-1. I have gone through 2 more 10k D-1 intervals since then and am about to complete a third... I need to update the PDF, huh. (Ooops.) I should have a good trend to display now. Soot averages 1% (approx) at 10kmi.
Finally... anyone see the specs on the new 2006 E420 CDI twin-turbo V8? Here's a thread with a link to some photos & techie details. Huge power, crazy fast... me want... probably not imported to the USA though.
Last edited by AMGDave; 09-01-2005 at 01:27 AM.
09-01-2005, 01:30 AM
#27
MBWorld Fanatic!
Yeah Dave, GREAT stuff here. I'm not up to date on the automotive diesels. I'm a former heavy duty diesel man. I never thought about the physical location issues of the new cramped engine bay. 
Big problem! I'm used to walking in the engine bay of a Peterbuilt!
420 CDI is a monster! I'd love to rent one on my next trip to EU. The 320 CDI was such a blast. I'll bet the new one kicks A$$!.
Big problem! I'm used to walking in the engine bay of a Peterbuilt!420 CDI is a monster! I'd love to rent one on my next trip to EU. The 320 CDI was such a blast. I'll bet the new one kicks A$$!.
