Aaron,

As mentioned, the CF rating was dropped from many mineral oils in the early to mid 90's to meet the newer Sx ratings such as SL. Synthetics can meet both SL and CF, but most mineral oils cannot.

__________________
Brian Toscano

Strange,most of the Light Duty mineral oils on the european market are CF/SL rated nowadays..also ACEA A3/B3 ...anda little more expensive than SHPD mineral oils...The price of sythetic is a killer- a gallon of Delvac 1/Shell Rimula/Castrol/Texaco Ursa is appr. $45

I thought the soot limit ,spcified by MB was 2% ,hence the 3000 and 5000 km limit on 61X and 60X engines..

Oil is tested and verified with soot content. At the time Mercedes was making these cars, the best oils could only handle 1 or 2 % soot. Many diesel synthetics can now handle 6% and a few 7.5% soot, and still meet the requirements.

So until your oil hits the maximum soot carrying capacity of the oil, soot is not the limiting factor.

4.5% soot level in 10,000 miles is very high. I would bet that's a car that's getting a lot of very low cetane fuel, or a lot of city driving, or has compression issues.

With fuel that meets Mercedes spec and mostly highway driving, 2 to 3% soot is much more likely in 10 kmiles.

10kmile diesel synthetic oil change intervals is a no brainer in these cars, and if you know what you're doing, a lot higher is no problemo. And that's not opinion, it's fact backed with lots of data.

Joe

We're still awaiting the data.

Good luck with your engine.

I did post data on the other topic that you shut down. I'll repeat it here again....


1984 Mercedes Benz 300D
3/18/04 to 8/2/04
2324 miles on sample
157168 miles on unit
Pennzoil Long Life 15W-40 CI-4
Mann Filter
3/4 quart top off
5 oz. of Soyshield in each tank of polished fuel

Fe 10
Cr 0
Pb 1
Cu 2
Sn 0
Al 4
Si 7
Na 0
Mo 48
K 0

Viscosity at 100C. 13.6
Water 0.2
Soot 0.3
Fuel 0
Glycol 0

Oxid 1.7
Nirt 0
SAE 43
TBN 9.6

Analysis by Oilguard

It shows soot at 0.3 for 2300 miles. That's 1% in 7500, roughly. So if you can go to 6% soot, which many synthetic diesel oils can do, that's 45,000 miles before the soot maxs out and the oil can no longer meet spec.

Even at 15,000 miles, thats only 2% soot. Now you will note he's using polished fuel. That does make a difference but at 15,000 you still have a huge engineering margin.

Maybe now you can see what I'm trying to tell you.

I can't figure out if you're waiting for data from my cars. You won't get it. I don't need that data. I can extrapolate from other data and base my actions on their results. No, it's not perfect....but it doesn't have to be.

I don't have to jump off a bridge to know it is going to kill me.

Joe

Your problem is that the data from some other OM617 may or may not apply to your own engine. These engines vary widely in the amount of soot produced and are heavily dependent on the type of driving and the condition of the engine. So, until you have the data for your own engine, you can't draw any conclusions.

And, for your information, the generally accepted limit for soot is 2%. As we mentioned to you on the other thread, you can run the oil until the soot reaches 7.5% if you like. It's your engine. However, you have no data whatsoever to support the wear levels in an OM 617 with 7.5% soot, so all of your statements are simply BS.

I've got the data for this OM617 and it shows that the soot levels are approaching 1.7% when the engine reaches 8K miles. I don't wish to run the engine right up to the 2% limit. But, hey, that's just me.

As I told you on the other thread, it's your engine.........do what you want.

Brian,

Seriously, you don't understand the oil spec. The oil meets its lubrication spec carrying 7.5% soot, or 6% or whatever they spec it at. It is tested at that soot level in a test stand. Soot causes problems when it clumps up. These oil have additives that keep that from happenning.

2% soot was the old ballpark figure that the oil was good to. There is NO engine spec that says 2% soot. They just knew at the time that if you hit 2% soot, the oil is going to give up and that's bad for the engine. Those days are gone.

Joe

I go 10K on my two 240s using Amsoil 15/40. The "79" had a small oil leak from the rear main seal (I screwed up installing the seal) Now it has almost completely disappeared.

I believe Delo 400 is, hands down, the best "dino" oil out there. I think all the tug outfits I have worked for use it.

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

I don't need to go 15K miles between oil changes to know it's not good for my engine.

Craig,

Well it's 2006. You can live in 1974, or 1984, but that doesn't change the fact that it's 2006.

15,000 miles on synthetic diesel oil, with a few conditions, is a lot less harmful than actually changing your oil more often.

Have you ever heard of Maintenance Induced Failure (MIF). I'm a engineer in the aircraft world. MIF is a serious issue there. MIF is also a serious issue when doing oil changes. Make a mistake and you might...might starve the engine for oil. I know the chances are very small if you are careful, but it does happen.

I know from personal experience and 25 years of data in the airplane business, that every time you do a maintenance action, there is a small, but non-zero chance of a terrible mistake.

With autos, you might lose an engine. In the airplane biz, you might lose 450 passengers and crew.

Joe

Although this is my first <10liter diesel, I'm running mine on Delvac 1/6-mo changes. It is not as good as Redline's syn diesel oil which is a polyolester stock, but it isn't as expensive either. From memory I believe it is around 10.5TBN, RedLine and Amsoil's Heavy Duty Diesel and Marine are 14TBN and 12TBN respectively I believe, I prefer to stick with 12 or better for an annual-change oil.

Holland Motor Express used to run their OTR trucks with Delvac 1, did a minor at 250,000miles at which time the oil was changed. This was about 2years' mileage. The filters were changed regularly (and to be honest Detroit 2-strokers pretty much changed oil as they ran), The result was less un-scheduled downtime (break downs), reduced oil consumption/cost, and reduced fuel consumption. I don't know what they do now, I no longer work with them.

The additive package does diminish even without use. You can not store an engine indefinately with old oil, the oil will break down with time. Regardless of the oil's brand and pedigree you will eventually need to either change it or re-refine it. There are filters for bigger engines (Lubrifiner?) that claim to extend the oil's life, but they cost more than the oil.

Not all "synthetic" oils are the same. The word "synthetic" can now be used on any oil regardless of basestock, provided it has been "cracked" a certain number of times, as it is then considered synthetic. Mobil 1 used to use a synthetic basestock, I believe that the only ones that do now are the Delvac 1 and the "Mobil 1 Extended" product. The regular Mobil 1 I'm told is a petrol basestock as are many other oils labeled "synthetic". Remember when "all natural" meant something also?

I will NEVER use a multi-viscosity dinosaur oil. To simplify, a 10W-40 dinosaur oil is typically a 10weight oil, with viscosity modifiers added to keep the oil thicker at higher temps and thus gain the rating 10W-40. These short-chain polymers are fragile, don't protect well in high-shear applications such as camshaft lobes, and break down. You're basically protecting your engine with SAE10 oil.

Synthetics earn their multi-viscosity ratings (at least in part) by naturally not thinning as much at higher temps nor thickening as much at lower temps. Mobil 1 5W-30 was (originally) produced with no viscosity modifiers, so viscosity breakdown and high-shear failure were not a problem.

One poster says he starts the car and lets it idle for 10minutes, most of us consider the carbon buildup under the top ring to be bad, and idling is a major contributor. It also creates lots of condesation and un-burned fuel in the crankcase, your best bet is to start the car, drive it gently until the temp is reading on the gauge. Any diesel manual I've read specifies not idling the engine for extended periods or for warm-up.

Another myth is the oil leak thing. Back when I recieved Roundel (sp?) I remember M-B's official stance was that synthetic oil could cause a leak to become more evident as the oil doesn't thicken as much as dino oil when the engine is cold, and therefore would continue to seep/leak. They continued by saying that if an engine "converted" to syn leaked more, just switch back at the next change or try part-synthetic. Simple enough. The myth started back in the mid-'70s when synthetic was new. We tried it because the arilines had switched all of their turbine stuff to synthetic, ... we had comparitive tests and data (compliments of the airline's lab) measuring metallic particles etc. in two premium dino oils plus Mobil 1 and Amsoil in our cars. The amount of metallic particles was vastly different between the synthetic and dino, only slightly better in the Amsoil than the Mobil 1, ... but I digress. Anyway, the myth: Oil in your engine reacts with rubber seals etc. with a finite and constant amount of swelling. You can see it on oil-soaked external rubber parts some times. This swelling of seals creates a certain position and interference fit between the seal and the part sealed (especially rotating parts). If a fluid is introduced that creates less swell, there is now a clearance between the worn-in seal and the mating surface.
Early synthetics didn't have the same swell characteristics and seals regressed, causing leaks. This was addressed with reformulations about 25years ago, but bad news travels faster than good news. Most synthetics have the same reactive/swell characteristics as the dino oils now, so they really don't cause leaks, they just don't stop leaking when they're cold.
Which is the next point: thick oil.

When you start your engine, especially in cold climates, the faster the oil pumps up to pressure the faster it can protect your engine. Starting your engine it has been said is the primary wear period of engines, it is also when the most contamination of oil occurs etc. If your oil is as thick as peanut-butter (as in a cold Michigan winter), it will not pump up quickly nor lubricate as well cold as a synthetic which is close to its normal viscosity when cold. Ditto for gear oils etc.

I also hate the dry-run of a fresh oil change, when the air in the empty filter casing is pushed through the bearings and displaces the oil there, ... a case for not changing the oil too often?

Oil useage: Dino oils tend to burn more and evaporate more, suffer viscosity breakdown more quickly. Normally the dino oils burning and evaporating shows up as oil useage where the more stable synthetic oils stay in the crankcase better. If an engine burns less oil after converting to synthetic (typical) it didn't "heal" itself, it's just running an oil that doesn't burn as easily so more oil is returning to the crankcase.

I have been using synthetic oils in my vehicles for almost 30years now, have done plenty of spectro-analysis etc. in the early years. It is IMO superior to the dino oil, even after thousands of miles vs new dino oil, provided there aren't other problems. I prefer to run annual oil changes, change filters at factory-specified intervals, and have no internal engine problems and a really clean valve train. Good filters are important, very important, and knowing whether your vehicle and driving are compatible with extended drain intervals is key. My wife's gas van, ... short-haul driving and idling at the school, not an extended-drain candidate. In fact she gets Delvac 1 and Mobil 1 filter every 6k.

A couple of final points I consider important. Never never never never (did I say that enough) use any products/additives containing PTFE (Teflon is a trademark so it might be listed as the generic PTFE). PTFE's breakdown temperature is lower than the temperature at which diesel fuel burns, ... PTFE coating the cylinder walls, "suck-squish-boom-go", burned PTFE is a good way IMO to make your rings stick in the piston and score your cylinder walls (as is carbon from extended idling). In fact I personally feel that buying a premium diesel oil (whether syn or non-syn) gives you a good additive package and really doesn't need any of the snake-oil additives (Slick 50 comes to mind) and unless you really understand engine oil you can very well make it worse by adding some of the off-the-shelf products.

That having been said, there are good oil and fuel additives, but good premium oil and premium filters (none of that Fram crap for my cars) will make them last a long time. Extended drain? For some good, for others bad. I don't suggest that anyone run oil change intervals that make them uncomfortable, changing the oil more often is pretty cheap maintenance really as is putting in good oil and filters.

Now how about engine coolant? Anyone? Is cavitation pitting a problem in these engines?

- Jeff Miller
'87 190DT

Interesting thread. I broke my 617.950 in on 15w40 Shell Rotella T and changed the oil the first time at 5000 miles. Since I drive the car on the freeway 108 miles daily (round trip) to work, I found it very difficult to keep up with a 3000 or 5000 mile oil change.

I ran the second oil change a full 10,000 miles and when I removed the oil filter, the lettering in the bottom of the oil filter housing was still visible. There was nothing that needed to be cleaned out. The housing drained away clean.

I had been accustomed to burning a quart of oil every 1,000 miles on this engine and I originally attributed this to the open 'tube' breather in the top of the stock camshaft cover. However, immediately after the oil change at 15,000 miles, things got interesting.

Overnight this engine just stopped buring oil. It went from a quart every 1,000 miles (with no visible smoke) to burning 1 quart in a full 10,000 miles.

The oil looked pretty nasty this time around, but again, the filter housing drained away clean, right down to the lettering on the floor.

In contrast, I have changed oil in OM 617's that had a 1/4" of caked soot on the floor of the housing.

I personally think that oil should be changed in a 617 every 5,000 miles. However, I have been unable to keep up with the service intervals and would not consider letting the local Auto Oil Changers mangle my brand new sump and drain plug.

On the other hand, a good friend of mine works for Burrtec Solid Waste in San Bernardino Ca. on their heavy equipment. He also works on over the road trucks. One company has been running the old mechanically injected Cummins 400 6 cylinder Turbos a full 10,000 miles between changes on Rotella T with very good oil analysis reports in between.

Any thoughts on this???...Bert

I agree with hot and often. With today's high oil quality often is every ten thousand.

Get with the times.

3000 mile oil changes were for the fifties.

Even new car manuals state every 6000 with dino oil.

If we all did this just think of the oil that would be saved every year.

Engines outlast most car bodies. Just my opinion!

Steve

Well guys, as an experiment (along with some laziness) I just put 10K miles on the oil (Mobil 1 5W40) in my 617 turbo (I normally go a maximum of 5-7K highway miles). These 10K were all highway miles, accumulated over about two months. When I finally changed it a couple of weeks ago, I sent the oil off for analysis. I'm still waiting for the results. At the risk of introducing some actual facts into this discussion, I will post the results when I get them.

We'll see what the analysis results say, but I don't expect to significantly extend my oil change interval (beyond about 7K). I still don't think I would be comfortable with 10K oil changes in a diesel, and I certainly wouldn't go much over 5K if I was doing any significant city driving. I just consider it cheap insurance. Hopefully, I will have the analysis results soon.

I did the same thing Craig. I was REALLY apprehensive about the 10,000 mile oil change interval (or longer). But I gave it a try and had an oil analysis done. My synthetic oil at 10,000 miles showed better oil analysis results than dino oil at 5000 miles. I'm convinced that 10,000 mile oil changes are fine on the 210 chassis. I'm still running dino oil in my 240D and have changed it every 5000 miles as the book recommends and will continue to do that.

Len
'99 E300TD 89,000 miles
'83 240D 345,000 miles original owner