Update

First I want to thank everyone who replied to my thread.
Today I contacted MBUSA and spoke to a tech.
This is what he said all MB engines made prior to 1999 were designed to run on conventional oil with frequent changes especially Diesel and that there really is no need to use synthetic oil as the engines will do fine on the regular oil as long as you use the reccommended rating oil and change it as recomended
I also called Amsoil and they said not to use there synthetic oil in a diesel with less than 5 thousand miles on it.But diesels require frequent changes and that I may want to stick with regular oil.
Then I called Mobil and they said only use the oil MB recommends.

So after all this research I'm going with Shell Rottela which is around $35. a 6 gallon case and change it every 3000.

rdanz,

What is the difference in engines made before 1998 and the engines made after 1998 that would make the earlier engines run on Dino oil and the later engines need synthetic oil?

I think it just took MB until 1998 to realize that synthetic oil was better so they finally specified it for their engines in 1998.

I have had good service from synthetic oils for over 180,000 miles in older MB Diesel engines. By changing synthetics at a 10,000 mile interval instead of a 3000 mile interval for Dino oil, there isn't much difference in cost.

P E H

Howdy,

I've got a question. Everybody here is talking about Mobil 1, but shouldn't we be sticking with a Diesel rated oil (i.e. Mobil 1 Delvac)? Is plain old Mobil 1 OK for Diesel useage?

I did my last two changes with Mobil 1 Delvac and am very happy with it. And, I've used Mobil 1 in gasser engines before, but is it better in a Diesel application when soot suspension is critical?

Sholin

__________________
What else, '73 MB 280 SEL (Lt Blue)
Daily driver: '84 190D 2.2 5 spd.

Mobil 1 is CF rated. CF is the rating for light duty and indirect injection diesel service. All automobile and pickup diesels ARE light duty diesels by definition. Mobil 1 15W50 is also approve by the ACEA specs for diesel service and by the Mercedes 229.1 sheet standard for passenger car (gas AND diesel). Mobil 1 0W40 meets all of those standards and the Mercedes 229.3 standard for extended change intervals and the Mercedes 229.5 standard for extended intervals AND improved fuel economy.

Mobil Delvac 1 oils meet the 228.3 standard for Mercedes direct injection high performance engines and extended drain intervals. This is a tougher standard, but is NOT required or benificial for the indirect injection engines that have been imported to the US. You can certainly use it (and I do sometimes) but it has NO proven benefit!

Here is a site that list the approved oils:

http://www.whnet.com/4x4/oil.html

Mercedes warns that just depending on the API or ACEA rating CAN lead to inappropriate choices for Mercedes engines. For example Mobil 1 xW30 oils are NOT approved!

In my opinion, there is no reason to NOT use conventional oil if you do mostly highway driving and change the oil frequently. You will not get the improved cold start ability of synthetic and cold start engine wear will be considerably higher, but if you drive LOTS of miles for every start, that will be minimal. If you are going to use conventional oil however, I really do suggets that you use one of the premium conventional oils. Chevron Delo 400 is about the best (according to oil analysis techs that have reported to me) using a mixture of class I and class II base stocks and a superior additive package. Mobil Delvac 1300 is good but slightly inferior base stock and superior additive package in their opinion. Shell Rotella is VERY ordinary - NOT bad oil but VERY ordinary.

Marshall

"Shell Rotella is VERY ordinary - NOT bad oil but VERY ordinary."
Marshall -
I called Chevron and asked about there oil and how it compared to Rottella and was surprised the tech said that its the same quality as theres since Shell reformulated there oil to meet the new higher standard.

That MAY be true - or NOT. Hard for me to imagine that a Chevron employee would tell you that Shell oil was just as good as Chevron oil - even if it was! I'd sure expect the Shell employees to thell you that Shell oil was BETTER than Chevron too. Now if they said they both met the same API standard, I'd believe that, but long ago I learned that the API standards do NOT rate the quality of oil, but only some particular properties. With the exception of Mobil (and then only after the president of Mobil introducted me to the head of research who introduced me to a team of their tribologists), I have not had any luck with the getting the people on the oil companies' phones to HONESTLY answer questions.

The tribologists at Mobil have been REALLY straight with me. Their answers have ALMOST always fit with what independent oil analysts have reported. The drivel I've gotten from other oil companies has been essentially worthless and was clearly outlined in the sales and advertising and not the research and technical departments.

Until I get word to the contrary, Shell Rotella is made from class I stock (the cheapest stock there is) while Chevron is a blend of class I and II (the largest percentage of class II of any major) and a superior additive package.

Marshall

Again I have lurked in the shadows and read all the arguements presented on the benefits of this oil or that. I, being an aircraft mechanic/engineer for the last 30 years have had the opportunity to observe the results of many different brands of oils, both petro based and synthetic, on the engines I have torn down and inspected; Both piston and turbine. After seeing the insides of literally hundreds of engines, I made the decision on what I run in my personal aircraft based on the wear characteristics of different brands. I run Aeroshell 80W Ashless Dispersant in my Lycoming O-360 and so far I have had absolutely no problems whatsoever. I also know that Pratt & Whitney recommends Shell Synthetic Turbine Oil for their turboprop and turbofan engines. That tells me something. If these companies are willing to stake their reputations and liability on Shell oil, then there must be something to it. It has not always been that way, so there also could be something to the claim that they are now using superior bases for their oils. I'm sure Mobil, Chevron and Exxon all have their benefits and are superb oils. But I will stay with Shell for the time being, Including Rotella in my OM 617.

__________________
83 W123 240D
76 300D, "Lil Yellow Car"
1978 Cessna 172N 180 HP Mod

"If life ain't fun, I'm not interested"

The important things are those that you learn after you know it all.
Chip Foose

Build a better mousetrap and you will REALLY infuriate corporate america.

As I've said many times, Rotella is NOT bad oil, just very ordinary. It's that way by their choice, not because they can't mix or sell a better (and more expensive) oil but because that oil is what MANY customers and you are willing to use. If lots of customers wanted better oil, Shell could provide it.

Ask half a dozen people that do oil analysis to compare Rotella to Delo 400 and report back!

As to the advantage of other oils. It can be measured. My favorite (although rather crude) measure is to establish the rate of timing chain stretch of a diesel over 50 or 100kmi using conventional oil. Then change to Mobil synthetic. The rate of chain stretch will decrease by more than half. I have repeated this test 7 times and the results are ALWAYS the same. One of the oils used in the first part of the test WAS Rotella. I have NOT performed this test with Delo 400 versus other conventional oils but have been assured that there is less wear then with most conventional oils - including Rotella.

Marshall