I have worked on German cars for 40 years. My cars all run Mobil One, or Syntech. Higher viscosity in the summer, lower in the winter. Common sense stuff!

For any of you interested in a very detailed technical paper written by three Mercedes engineers,titled "Extended Oil Drain Intervals - Conservation of Resources or Reduction of Engine Life (Part 2)" May want to order this 23 page paper Number 981443 from SAE (Society of Automotive Engineers) at http://www.sae.org/BOOKSTORE The cost to download is $10.00 After reading this paper you may not feel guilty about extending your oil change intervals considerably.

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Tom H.

Thank you for the link - this constant talk about "every 3000 miles or else" and "don't worry about 7000-10000 mile drain intervals, you'll only get sludge" represent a very conservative approach at best and unsupported anecdotal heresay at worst.

BMW has had variable service intervals since the early 80's and now the other manufacturers are going that route including MB (err should I say DC). While certainly our highest priority is to prolong the life of our beloved MB motors, I feel we should be open to the currently accepted engineering wisdom as well as understand the ramifications - both on our pocketbook as well as the environment - of rushing out every 3000 miles to change our oil ....

My $0.02 - thanks for the bandwidth!

Brian
Mobil 1 15w50 year round ('less its *really* cold)
89 300TE 150K
84 733i 5speed 145K
somewhat extended drain intervals
verified by oil analysis

The 10 bucks to download that article is more than enough for me to buy enough oil for another change.

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Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired

Is changing your oil work or play? For me it's definitely play!

Kuan

I switched from Mobil 1 from the Chevron Delo 400 oil for my '87 560 SEL. All the MB dealers out in LA use 15W-40 even for the gas cars. That is what I use for my '92 400E still but, with the 560. I use 15W-50 Mobil 1. Depending on the climate I suggest any oil except, Castrol Syntech, Quaker State and Penzoil. Due to paraffin content. People have complaints on those.

Tom,

I'm glad to see that there are more engineers joining this forum and contributing their knowledge. The paper you suggest looks like it would be quite interesting, and while I am a staunch believer in protecting intellectual property, I am wondering if you, or someone would be willing to give us a book report, the Cliff's Notes if you will. I just would like to know what the jist is.

And taaboo,

I can't completely agree with your comment, "...this constant talk about "every 3000 miles or else"." All I recall anyone saying is that THEY choose to change their oil at those intervals, and what others choose to do is entirely up to the individual.

And as to MB vs DC, MB is still correct, as it is the division of DC that we are most concerned about. DaimlerChrysler includes vehicles from Mercedes Benz, Chrysler, Dodge, Jeep, Thomas, Setra, Western Star, Sterling, Freightliner, American LaFrance, and Smart. As well as components from Detroit Diesel, MTU Friedrichshafen & MTU Aero, Mopar, Powerline & Temic.

http://www.mbusa.com http://www.mercedesbenz.de http://www.daimlerchrysler.com

BTW, during a recent conversation with an engineer at RedLine Oil, http://www.redlineoil.com, I was told that the normal drain interval for their synthetic diesel engine oil when used in my car should be 13,000 to 18,000 miles...

And those of us who are already using synthetic oils are helping the environment by not relying on fossil oils. In return, we are rewarded with better fuel economy, better lubrication, and no sludge in our engines, as the synthetics do not have any wax or paraffin in them!

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."

I can agree with the statements that oils and engines are built better now, so you can go longer than the old idea of 3,000 mile intervals. The question though would be when did it change.. I mean just because oils are better now, does that mean an engine that was designed around 3-5k intervals can now magicaly go the 10-15K interval. Yes "new" cars run much cleaner so the longer intervals can be done, but what about those of us driving cars that much older than what is considered "new". I doubt very much that with my diesel at nearly 228K miles can just suddenly change to 10K mile oil changes just because the oils are "better". I don't mind going 5-7K oil changes in my VW Passat because I have had since it was new, VW recommends 5K intervals of reg. oil, and I have been using synthetic oil (Valvoline Synpower 5W-40) since 10K. So basicly, what is the driving factor in the intervals, the quality of the oil or what the engine was designed for.

__________________
1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

Longston
SAE Paper 981443 describes experience from over 2.5 million miles of field trials and dynamometer tests with different MB engines during the development of the Flexible Service System. Analysis was made for Police, Taxi, and "Normal" use.
Although the oil brands used were not specified, the five authors, in addition to the three MB engineers, included two from Shell.
The objective was to determine the aging of the lubricants as related to vehicle use. I'm a two finger typist and it is not easy to type a long analysis of this paper, nor do I want to violate any copyrights, but I will say this, after reading this paper, anyone using a reasonable quality oil who is not operating a taxi or police car, should not find it necessary to change oil more frequently than MB recommends in the owner's manual, unless they enjoy doing it.
Since I also enjoy working on my cars, I change the oil about every 6000 miles(w/o filter change), about half way between the recommended mileage/time shown on the FSS, but I don't feel guilty if I miss a change for some reason.

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Tom H.

U know there were several articles about 10 years ago. What was weird about these articles were that people were going 100 of thousands of miles without changing the oil at all. They only changed the filter. This was published in BMW club of America. They even did some oil analysis saying, that the engine was ok. They were emphasizing that the filter was the most important thing. It was weird. When I waa in a mechanic's tech course. They emphasized that both had to be changed out due to detergents. I feel the same but, it was so weird hearing not just one or two people testifying to this but, several on different cars. I thought I had joined the Twilight Zone club or something. I do change oil and filter every 3000 miles on a regular basis but, looking back at those testimonials made me wonder. How cheap can these people be or maybe they know something all of us don't.

Obviously we have two different uses being discussed here, gasoline and diesel. Using the same oil, a good universal 15-40 diesel rated oil, when it is used in my gasoline cars it is good as new after 7500 miles, but when used in my diesel I change it every 3500, along with the filter because about that point the level starts to drop, i.e., I have to add more oil. The oil seems to wear out with use. It is being constantly polluted with more and more carbon each day, and the filter certainly doesn't take it out (being sub-micron), perhaps there is a displacement thing going on here. Does anyone else notice the "wear out factor" in relation to diesel use?

__________________
'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles

I am printing out the SAE paper to read as I type this. My '86 with 295k has had semi-synthetic (Lubri-Moly) or, more recently, fully synthetic Amsoil for the last 120k miles. Changed every 18k miles now, actually every six months (I drive about 36k annually), with the filter being changed at three month intervals.

Having studied the synthetics quite a bit, I will probably never go back to fossil-based lubricants in anything. My brand new Kubota diesel did not come home from the dealer until they put in the Amsoil products I took them. It will outlast my MBs because I hardly use it!

At our new house we are putting up a refurbished wind generator. We live in the boonies (and love it, btw) and the wind blows a lot in Nebraska. They man I purchased it from and who is installing it puts a brand new warranty on them, UNLESS you add something to the gear lubricant. The only turbines to ever burn out that he put in have had something added to the lubricant - including but not limited to Slick 50. The only lubricant he uses is Amsoil. The important part is not the brand, but the fact that it is synthetic, so therefore cannot and will not burn up. He changes this lubricant once a year, btw.

I know this is not a car engine, the it is similiar in that the turbine turn very rapidly, but, naturally, there is not a problem with pollution from hyrdrocarbon fuels.

Who has experience with Redline synthetics? I just started using their Diesel Fuel Catalyst, which seems to help my car run smoother.

changing the filter is definitely important. I would tend to side more with the guys changing filters more often than oil than changing oil more often that filters. All modern cars are equipt with a filter bypass system, so that if the filter becomes clogged the engine can maintain oil pressure. This means that if the oil is not easily passing through the filter some or all of it may be bypassing the filter, which - short of running without oil - is one of the worst things that can happen. If you do extend your oil changes, whether using synthetic or not, its probably still a good idea to change the filter at prescribed intervals. I am sure that given these modern oils that the filters probably loose efficiency before the oils will. I still like to change my oil more frequently than most, and I do believe that I will be rewarded in the long run.

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Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired

DrT,

If you have not changed the timing chain in your SDL, I would highly recommend that you, at the very minimum, check it for stretch. Extended oil change intervals leave microscopic particulate in the oil which will cause premature timing chain wear. The consequences of a failed timing chain are, of course, catastrophic.

The rest of the engine may be reasonably well served by your oil change frequency.

Longston,

Fabulous reply!

Have a great day,

http://www.audiworld.com/tech/eng12.shtml

and

http://www.audiworld.com/tech/eng9.shtml

just some more info for the active reader!

__________________
2000 Ford 7.3 Powerstroke 4x4
2006 Mazda Tribute
1983 Black 300 D (donated to charity)
1993 Teal 300 D (160K) Sold
"I love the smell of burnt diesel fuel in the morning, it smells like ....VICTORY"

Semper Fidelis
USMC 1973-1976