I changed over to Mobil 1 Synthetic oil at 181,471 miles in my 1985 300D. I now have 184,856 miles. I checked the oil and noticed that it is exceptionally black. Do you think I should change the oil again. My thinking is that because I switched to the Mobil 1 a lot of dirt and grim has been released from inside the engine and maybe for that reason it should be changed again along with the filter. It has only been just over 3,000 miles since I changed it originally. Also, what is the best synthetic motor oil to use for my car? Thanks in advance.
ed

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Ed
1985 300D w/ 196,000 miles

The oil in your car should be black all the time. Do a search, I believe that Mobil 1 does not meet the standards for diesel oil. I could be wrong.

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2001 Dodge Ram 2500 Cummins Turbo Diesel - 4x4, auto, 3.54 gears, long bed
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'92 300D 2.5 Turbodiesel - sold
'83 300D Turbodiesel - 4 speed manual/2.88 diff - sold
'87 300D Turbodiesel - sold
'82 300D Turbodiesel - sold

I put Mobil 1 in my 83 300D and it LOVES it. Quieter, smoother, faster, quieter on the highway. Only thing I dont like is that it isnt a diesel rated oil.

Look for Mobil Delvac 1, synthetic diesel rated oil.

John

I believe Mobil 1 is okay for use in light-duty diesels. Doesn't Mercedes now specify Mobil 1 for use across its model range, including diesels?

Aaron

I have several questions related to synthetic oils.

1) Do you have to flush your engine before switching from dino oil to synthetic? Or can you just add it straight without doing anything special?

2) Does anyone know where I can buy Mobil Delvac 1 online? There is absolutely no where around where I live that would carry anything like it. I have Delvac 1300 in my car now and I would just like to try the synthetic stuff for comparison.

Ed,
I've always wanted to try Mobil 1 so I suppose that if it's worked well so far, there's no reason to get rid of it. Oh wait, that wasn't your original question, you asked whether or not you should change it. I would say that after spending all that money on the synthetic, you might as well leave it in for a little longer. If it were my car, I'd probably do the change at 5,000 miles. If you want to try something new, just for a change of pace, I get my Mobil Delvac 1300 industrial stuff really cheap locally around here. I'd be more than happy to go with you and get it or pick some up for you. It comes in a case with 4 one gallon bottles for about $24; much less than everywhere else I've seen it. There's also another place (in Port Chester) that sells Shell Rotella in 5 gallon buckets for $35. I like the idea of having it in a bucket with maybe a pump attached to it (like a beer keg). Just some ideas....

Alex

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1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

it says on the bottle of Mobil1 synthetic that it is suitable for Diesels. I read every label of every motor oil at Pepboys. Most of them don't even say Diesel on em.

I was told my a friend of mine's dad (fleet manager for the City of Richardson) That there was something in Delvac that once you switch over to it you can't switch back becauce it coats the engine where other oils can get in to lubricate. I was going to get Delvac 1300 (the Dino version of Delvac) because I couldn't find Delvac1, but after a long dilberation I chosed regular Mobil One because it said Diesel on it. So far it's worked wonderfully.

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2005 Audi A4 1.8T CVT -Silver/Black "Siegfried"

1982 300D - Silver/Blue "Ralph" -For Sale:
http://www.peachparts.com/shopforum/mercedes-benz-cars-sale/119226-1982-300d-sale.html#post852260

1989 VW Diesel Jetta Blue/Blue "Bodo" RIP

You mean to say that I couldn't switch from Delvac 1300 to Mobil 1 if I wanted to?

Crap!!! I really wanted to try the regular Mobil 1 stuff.


Alex

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1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

Dino and synthetic oils are absolutely compatable...no steps are required to switch over. As to Delvac One "coating" the engine, I've never heard this-however, ANY synthetic oil has a propensity to linger on parts longer, apparently being very "clingy" if you know what I mean.

As to locating Delvac One, I suggest you track down a phone # for Mobil Corporate and find out who the distributors are in your area. Good luck!

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"If God had meant for us to walk, why did he give us feet that fit car pedals?" Sir Sterling Moss

Michael
2014 E63S Estate
2006 SLK55
1995 E500
1986 Porsche 944 turbo

Check out farm stores. They carry a lot of stuff for diesels. The one near me has Delvac 1, Delvac 1300, Rotalla T, Rotella SB, Penzoil 15W-40 in 2.5 gallon containers, and Delo 400 (along with their discount brand -- Mystic, made by Citgo if I remember correctly)

All of these oils carry the higher CG-4, CH-4 diesel ratings. Mobil 1 is only rated CD I believe.

Mark

You can still use Delvac One, he didn't say anything about that (switching between Delvac 1300 and Delvac One). He just warned about putting Delvac in, then trying out a different oil. Personally I would have gotten Delvac One, knowing what I know, but the regular Mobil1 Synthetic is just fine for the MB Diesels if you can't find Delvac One anywhere.

EDIT: Just clarifying

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2005 Audi A4 1.8T CVT -Silver/Black "Siegfried"

1982 300D - Silver/Blue "Ralph" -For Sale:
http://www.peachparts.com/shopforum/showthread.php?p=852260

1989 VW Diesel Jetta Blue/Blue "Bodo" RIP

Mobil 1 is ok for diesels, in heavy use engines there is a problem with it foaming up because it doesn't have as many additives, if you have that problem i believe there is an additive that will keep it from foaming. Amsoil is good stuff, it's expensive, you can order it on-line though. I use it in my Ford Powerstroke, the Benz leaks a little too much oil for me to use something that expensive.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

Mobil 1 and the other synthetics are the only oils are the autoparts stores (typically) that have any sort of diesel rating. They are also the only ones rated for turbocharger use.

Oils rated CD are just fine for MB diesels, as that was the latest rating in the early 80's. I'm positive it is better than dino oil for my 220D!

And yes, it would be a good idea to change the oil at 3000 miles after changing to Mobil 1 on an older high milage engine -- I'm sure the oil filter is full of all the crap that was stuck to everything all over the insides of that old diesel -- it is shiny clean now! Oil in diesels turns black pretty fast, even in nice tight new ones, from the soot produced. Not a problem, as the particles are far too small to cause trouble, but in a old engine there will be a considerable amount of hard sludge and other nasties stuck all over, and all this comes off pretty fast once you put the synthetic in. You can extend later oil changes to whatever mileage you would like. Just change the filter ever time.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Well, whaddya know. I just checked the back of my Mobil 1 15W-50 (for my Gold Wing), and there it was: SJ, SH/CF. I've been using the 10W-30 in my gas Mazdas (and the next oil change in my bike will be the 15W-50), and I've never noticed that. I had a VW diesel Rabbit, and used Rotella in it.

By the way, this is my first post. I truly am glad I found this forum as I am in the market for an 80's MB diesel, getting closer to purchase each day. I've spent a lot of time here recently "catching up"

Dave

I've been doing some research on this subject in the UK as I'm moving over to Fully synth oil for my diesel.

According to the specs in my vehicles documents Mobil1 oil doesn't meet the specs for the 90's 300D or TD engine.

In Europe Mobil do sell an oil "Mobil1 Turbo diesel "which does meet the MB diesel specs.

On Mobil's US web site it says Mobil1 is not to the correct spec for MBs and recommends Mobil Delvac.

We can't get Delvac in the UK so I'm not sure if Mobil1 Turbo Diesel is the same as it can also be used in trucks.

I have asked Mobil technical help desk about this and was told never to put Mobil1 in a MB diesel and to only use the turbo diesel version. No explanation given though.