G-Man (do you have a name?):

You are probably right; I was referring to petroleum-based oils, not synthetics.

However, if you would just look at your oil (pull out the dipstick) at 3,000 miles, you will see that it is no longer clear, but now black. Not brown, not tan, but black. This does not mean that the oil has degraded, but rather that it is dirty. Why is it dirty? Because the combustion process creates particulant byproducts, and these are the things that can "ruin", or score, or affect, your engine.

There are reasons that detergent is used in all "oil" and gasoline products, and that is to keep injectors, valve, etc clean. But where do you think all this stuff that is being scrubbed off or from injectors are going? INTO YOUR OIL.

So, most of us who believe in the 3,000 oil change do so as VERY cheap insurance. In fact, if you do your own oil changes, it is only the cost of oil. And for 6 quarts at $1.50 per quart, how much insurance can you afford?

But I still don't understand why this is such an emotional subject!! It's as if so many people out there treat oil changes as a religion, and you all have read how religious wars can hurt innocent people. Let's just all of us get along, do our own thing about oil changes , and move on to really useful information about how to fix and maintain our wonderful Mercedeses.....Cheers, Andras

well said andras!! besides, the owners' manual has a chart on varying temperatures and recommended oil weight usage. trust the makers of the product, they know better. rock on!!

It wasn't my intention to be insulting, I just feel as though the Jiffy Lubes of this world have created the impression that if you don't change every 3k that your car will certianly die an untimely death. I happen to disagree as do all of the manufacturers of automobiles I am aware of. I've never seen them advocate 3k changes and thier reputations and profits demand the product lasts. But to each his own, the money I save on this type of overkill will help to fund another wonderful auto (928 Porsche) so I can put fewer miles on all of them! But your right lets drive!! P.S. my name is Brent

------------------
90 300GE 5sp
95 740iL

Brent:

Thanks, no insult taken.

If some of us who advocate changing our oil at 3,000 seem to be enthusiastic about it, it is because we do it ourselves, and do not trust JiffyLube, and others to do it. When one does it oneself, it is just the cost of the actual oil, and therefore somewhat insignificant.

As to manufacturers, please realize that there have been government and marketing pressures (in all nations), for manufacturers to develop "maintenance-free cars". That is why there are some out there who claim 100,000 miles no service in their ads. But would you truly not do anything to your car for 100,000 miles? I guess if you were leasing your car you might, but even Audi and some others build in the cost of maintenance, with free servicing for the first part of the life of the car.

However, once again, I invite you to inspect your oil at 3,000 miles, either through the dip stick, or just humor me, and change your oil at 3,000 and see how black it is. Oil does not literally "wear out" but it gets dirty, and thus can cause lots of little problems with components, which can accumulate and create big problems.

What is interesting that such a minor cost (when done by yourself) can generate such "rabid" opinions. Go to the other Marques sites, such as Porsche, Miata, etc, and you'll see the same concerns expressed there (and by the way, see the same polarization between the 3,000 mile guys and the 10,000 mile guys).

So if you plan to keep your car to the 200,000 mile mark (to infinity and beyond?), note that the guys with the high mileage all advocate the 3,000 mile change.

Hopefully we can make this subject RIP....Andras

Well, I don't want to help beat a dead horse, but I remember reading a discussion in the archives about not changing the oil every 3000, but only the oil filter. Again, there was quite a division in the masses on that topic and I don't want to re-open the debate, but I have tried that method (if only out of curiosity) and haven't noticed a remarkable change in viscosity, engine temp., etc. Half of me says that oil is so relatively cheap that I should just change the whole works every time, but I guess there's also something to be said for not getting rid of seemingly good oil just because the ododmeter says to. Any additonal thoughts?

One must remember what the original question was......

Yes this is a very popular subject for debate, and I have studied this thing for a long time, but there can never bee to much debate, however this posting has taken the way of many offramps, so it has lost some of its intent.

Just some clarifications for all...


1. The benz manual is useless in telling you much of what to do about an oil change. My 98 Manual is proof of this. ( So it is okay to ask)

2. Yes it is true that it is not a good idea to use diesel oil in gas engines. ( Plugs will foul)

3. Dont try to compare diesel vs gas unless you know the difference's, it will save embarrasement.

4. 20W-50 is a little heavy for Chicago's winters.

And here is something that the new 98 diesel engine owners will find interesting, I have found out that over a period of time the viscosity index will actually increase, due to the accumulation of soot in the oil. This is only on the new engines.

5. Knowledge is Power, it's up to you to apply it.

A very slippery subject indeed

All pun intended.

------------------
Chris Ecklund
98 300 DT

My .02 worth:
If you can afford a Benz, you can afford to change oil and filter every 3000 miles. As stated by others, it is THE CHEAPEST way to insure that your Benz engine will last a very long time, and that you will obtain the highest price for your car at trade-in or resale time. My Volvo 240 has 219,000 miles on it and uses NO oil ever, and I attribute this in part to religious 3000 mile oil and (Mann) filter changes over the life of the car. If you were buying a used Benz, all other things being equal, would you buy one that had had oil changes according to the computer, or one that had had religious 3000 mile oil and filter changes? Ahh, I thought so!
Best regards to all,
Colin

I'm also in AZ (Tucson) and both MBUSI and Mobil told me that Mobil 1 10W-30 was the right choice in spite of the high temps. Mobil claims it protects as well as 10W-40s and doesn't require as much "viscosity adjusters" in the mix as an oil with a wider spread, like 15W-50 or 5W-30.

Between their advice and an 8 year extended warranty, that's what I'm using in my ML320 and E320.

GMan and Andras,

Okay this is enough!<g>

I can understand where both of you get your opinions regarding oil changes, and you both make good points. However, Andras is pointing out some very interesting facts. Where do those contaminants go? As for all the automobile manufacturer recommending 10K mile intervals; first of all they would like to sell you another vehicle and soon, secondly, they were recommending 7,500 mile intervals back when G-Man was agreeing that 3,000 was a good thing.

I drive 60,000 miles a year mostly in Mercedes, a gas and a diesel. The diesel went 380,000 miles before the first engine overhaul. I know this is not scientific statistical analysis, but it must mean something. This 380,000 miles had the following admittedly FANATICAL oil change interval/method:

3,000 mile intervals
Chevron DELO 15W40 multigrade(truckers oil)
preferable drain time, Friday night
Pull the plug as soon as possible after killing engine(engine as hot as possible)
Drain at least over night, maybe 'til Sunday
Change filter every time
Replace plug, fill filter housing
install filter
Crank engine and log in book

If you don't have facilities to take such fanatical measures, go to the JiffyLube, but go there when your engine is at operating temperature.

Draining the oil from a cold engine, leaves the vast majority of the contaminants "stuck" to the parts inside the engine.


Good luck and keep changing that oil.

I hope none of the beginning comments insulted anyone, they were in fun.

Best regards,
Larry Bible

PS Even though I'm in Texas I'm not a salesmen for an Oil Company.