I copied this post from the forum on the Mercedes Benz Club of America website.

Just thought it would be an interesting read for those who think Synthetic oil lasts forever:

"Earlier today, I saw a failed engine on a Jeep Grand Cherokee that is interesting to consider. All the engine bearings failed. The bearing inserts saw high heat. They and the connecting rod caps are black. The crankshaft is ruined. It looks like the fix is a new long block. The engine was using a synthetic oil which starts with the letter A and is distributed by independent distributors. The owner had the idea that this fabulous synthetic oil is good for many, many thousands of miles of around-town driving with filter changes every 6 to 7 thousand miles. The oil had 27,000 miles on it at time of engine failure. The tech believes that the engine failure is directly related to the owner's failure to change oil on a regular basis."

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Conversely, one can say the engine lasted 27,000 miles. I've heard stories where engines with regular oil were neglected and lasted the same amount. I mention this because sometimes - when reading oil threads - I get the feeling regular oil is underrated.

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95 E320 Cabriolet, 159K

Anybody that accumulates 27 k mile with the same oil qualifies for the " Idiot of the year " award.
Actually, sad as it was, a friend of mine, a few years ago, was also using the " A " oil, changing filters only at 5 k mile intervals ( as recommended by the same " A " company ).
After two destroyed engines ( to which " A " company had no comments ), he finally adjusted his oil & filter change intervals to something more reasonable.
He also changed to the " M " company for all his oil, and has experienced many trouble free mile since.

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2007 C 230 Sport.

One word, stupid stupid stupid. 27,000 miles eh, is this a record? I wonder what gave this person the idea that synthetic oil would last forever, even teflon wears out over time.

Manny, wouldn't the "A" company be liable for the destroyed engines if it was claimed that only filter changes would be needed when using their product?

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)

Back in the late eighties I was at the dealer and there was a 190E 2.3 in the service lane that had a ticking engine. My service advisor told me that the owner had never changed the oil, and the car had about 25K miles. Of course, it was still on warranty, but MBZ would have been justified for not honoring it because the owner did not observe the 7500 miles or six month oil change requirement.

Most new cars that require synthetic oil have oil quality monitoring systems that tell you when it is time to change oil. If you have an older car and want to use synthetic, I would not go beyond 10K miles or one year, which renders synthetic not cost effective, because it is at least double the price of conventional oil.

Back when I was driving my 190E 2.6 every day I changed the oil and filter every 5K miles, which worked out to about three times per year.

Since none of my cars accumulate much mileage now I change the oil and filter every year - use conventional spark ignition engine oil (API service category SL) on modern cars with catalytic converters and HD diesel engine oil (API service category CI-4) on the vintage cars without converters. CI-4 oil has a richer additive package that is good for the vintage cars with carburetors that tend to suffer more oil dilution due to imprecise mixture control, but the combustion byproducts of these additives are not kind to converters. Also, modern fuel injected emission controlled engines have much more precise fuel metering, so they don't necessarily need the additional additive concentration of the CI-4 oils.

Bottom line - unless you're an engineer with plenty of experience in engine lubrication requirements, follow the manufacturer's recommendation for oil change interval and service products.

Duke

Big difference if you get this " expert" advice verbally or written.
He also used their auxillary by-pass filter, which gave him "added protection".
If I remember correctly ( old age is a ***** ), they offered him a case of oil & filters as compensation.
The value of two engines should have been two cases of gold bars.

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2007 C 230 Sport.

Interesting discussion.

Oil changes are a MUST, no matter what oil is being used.

On the recommendation of my mechanic, I switched away from synthetics on my 560 SEL with 104k miles on it. He felt that you should change the oil and filter every 3k to 4k, and the cheaper, standard oil is just fine for those inervals.

Why?

Because of sludge. He felt that by streching the oil changes using synthetic, the risk of sludge clogging is higher. So if you shorten the interval, you lose the benefit of the synthetic, and you're just blowing away dough.

He has a 500 Convertible.

He charges $35 per oil change. I'm not complaining.

Oh yeah, I once stretched the oil change on a Volvo 240 D. Interesting experience, when the bearings of the cam freeze, you snap the timing belt, etc...

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Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)

All this reminds me of a conversation I had years ago with the owner of a '53 170S diesel which was written up in an MB newsletter because he was about the turn over 800,000 miles with the original 4 cyl. engine. He commuted 260 miles/day to work. I asked him what kind of oil he used & how often he changed it. His reply: RECYCLED oil but he changed it every 2,000 miles!

Someone else who was written up in The Star awhile back is about to put the same mileage on his '59 220S (orig. owner). Used nothing but 10W-30 fossil but again dropped it every 2,000 miles.

Both these cars started out when motor oil was no where advanced as it is today. Yes it does say something about regular oil & changing it hot & often.

I'm amazed at how people concentrate on saving a few bucks on oil when maintenance has so little impact on the cost of ownership.

I use Mobil 1 and change it every six months or 3,700 miles, whichever comes first.

Using OEM filters, it costs me less than $30 for an oil change. I can't even buy my wife lunch for that any more.

It's rediculous to worry about the cost of oil when a new MB engine costs more than my first house.

BTW, a true synthetic will greatly reduce the possibility of gelling/sludge. I would never use the so-called A oil. They will never give you a staight answer about things and make rediculous recommendations and claims.

Sigh!.!......

Penny wise and pound foolish.

I worked at North Texas State University back in the seventies. There was a high level professor there who absolutely insisted that there was no reason whatsoever to change oil at any interval. You would think someone with enough intelligence to earn a PHD would be able to listen to reason.

His work car was a little red Japanese car of some sort. I don't know how long it lasted, but I do remember that when I left there to work elsewhere the car was "blue smoking."

Have a great day,
Change oil hot and change oil often,

This is my last word on this topic.
Even with synthetic oil ( which I use ), do not extend the drain intervals.
Read the can or bottle, it always says: FOLLOW VEHICLE MANUFACTURERS RECOMMENDED DRAIN INTERVALS !
To me personnaly, the point of using synthetic is not to squeeze more miles out of it, I just get more peace of mind from it, than from dyno juice.

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2007 C 230 Sport.

Synthetic oil has one major advantage. Extreme conditions! If anyone ever severely overheats an engine due to cooling system malfunction, synthetic oil may be the difference between an inexpensive repair and a catastrophe. I've seen synthetic oil save the day many times. There's no mistaking the smell of cooked oil (big bucks) when diagnosing/estimating an overheat repair.

I change mine every 5,000 miles, the mid ground between 3500 and 7500 miles as stated in most owner manuals. I drive some in town and mostly out on the highway or freeways. So far when doing an oil change the oil is still clear but a dark amber color. I get a change for about 30 bucks and most of the time they let me into the pit to give the underside a look-see. I used to do it myself (for about 20 bucks) but it's getting harder and harder to crawl under anything any more.

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1991 300SE (my ride, 279,000 miles, looks almost new
1954 Cadillac (21 yo son's car, he bought when age 15)
1972 SeaBird 19 ft runabout (old but solid, slant six, Volvo sterndrive perfect condition, undergoing complete overhaul and refit)
1998 Toyota Rav4 (my sons daily driver when he is in the Continental US, PROUDLY serving in US Navy)

Interesting. As the one stated, the engine was doomed to fail regardless of oil used. I ran A HDD 5w-30 in my 2000 VW Jetta with an A bypass filter and (with oil testing) changed the oil after 53,000 miles. At 120,000 miles compression was 550-545-555-550. Bearings looked new and there was no buildup in the engine, anywhere. I changed the oil in my MB diesel every 6-10Kmi using syn. The mechanics say it runs like a gas car and that I'd need to get a V8 for comparable performance. Its very clean inside at 279Kmi. There is more than one way to change the oil in car. Some say hot and often, and others say that's a waste of time and resources when considering synthetics. Both seem to have good luck and bad luck from time to time.

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Brian Toscano

On my Benzes, I change as close to 3,000 as possible. Change my boat engines twice per year, or abouyt every 25 hours. Other currently owned cars around 5000 miles. Hoping for ling life.

But....

When I was around 18, I bought a used 1970 Chevy Impala from an estate with a 350 and a turbo 400 (came like that from the factory!) It was a light green 4 door with a kinda green, kindaq tan plastic interior. I got it for a song and what the heck, it was my beater. A good beater because it only had about 34000 miles on it. Well, this car turned out to last much longer than expected. In fact, I kept it till it had over 200,000 on the odometer. I then sold it to a buddy that gutted it and ran hobby-stock at the local 1/4 mile asphalt roundy-round. I never, ever, not once, changed the oil. Ever. Added about a quart every 5000 miles or so. Never changed the filter. Granted, most of the miles were highway miles going back and forth 50 miles each way to school. My buddy did not change oil either, ran and won a few races, then plowed it into the wall. Who knows how long the engine would have gone.

When I got a different job about 45 miles from home a number of years later, I decided driving a 15 MPG GM Cutlas car was not going to cut it. I saw a brown 1986 Nisaan Sentra, 4 cyl, stick shift, no air, am/fm radio with about 40,000 miles on the clock. This car had brown outside, brown plastic seats, and a brown plastic "carpet". The owner sold it soo cheap, I figured the odo was rolled back. I just needed 40 mpg for a while till I could afford a car I could be seen in. Considered tinting the windows! Anyway, with no intent on keeping the car long, I again drove it to death. Changed a clutch once, a few brake jobs, tires, exhaust, timing belt, etc, but never changed the oil. Again, not ever, not even right after I bought it. At about 190,000 miles, the trans broke and only worked in a couple of gears. It went around 150,000 miles without an oil change, just an occasional top up with the cheapest oil I could buy. I gave it to a neighbor when I moved. Probably still running.

I bought a used Plymouth mini van because my wife said I needed one. I hate the thing. So I want it to go away. So I decided that it was luck with the Sentra and the Impala; I'll just say I change the oil in the van, but don't, and hopefully the thing will simply lock-up. Well, 6 years later, and no oil changes, the WPOS is still going strong. Pulled a camper trailer with it over the rockies with it (mostly in second gear and lotsa rpms), and a 17' drag boat back over the Rockies, again in second gear most of the way. Sucking some oil throught the valve stem seals at idle, but it did that when I bought it. Van had about 90k on her when I had to buy it, now has almost 200k. Still pull the drag boat with it.

So, tell me again why I have to change the oil so often in my current engines? I have hard experience that shows I don't have to change oil. This guy with the 27,000 miles on synthetic that had overheated bearings, maybe it was not oil related? Maybe he ran it low on oil? I've seen many many engines fail because of low oil, but have yet to see one fail from type of oil or length of oil change interval. Or because of an overheating condition in the cooling system, causing a breakdown of oil. As for severe service, cheap dino oil is what I used in my beaters. And I think I have severely overloaded the minivan. I hate that van but it sure has been good to me. A lot cheaper to run than a Benz!