Dave, you and others have stated that Mobil 1 is a true synthetic. I like Mobil 1 and use it in my cars, but there was a link to some article here recently written by some Canadian and he seemed to imply Mobil 1 isn't a true synthetic, only Redline and Amsoil. What's your take on that? Redline and Amsoil are more expensive and probably superior, but I don't know in what way.

Sadly, the same company sometimes ships different products in different countries. For example, some Castrol Syntec oils in Europe are Group IV/V, while we get the crappy Group III Syntec over here in the USA. The opposite seems to be true for Mobil, we get good stuff in the USA, but other countries may get Group III. Same product name, different product in the bottle! Nice, huh? I'm assuming the Canadian stuff may be different. Often the viscosity is different as well, I've heard of a Mobil-1 5W-50 for example that may be a Group III oil.

Anyway, AFAIK, all Amsoil and Red Line oils are true PAO Group IV/V. Of the two, you can get Amsoil cheaper if you try hard enough, down in the $4-$5/qt range (same as Mobil-1). Red Line is usually another couple bucks per quart. I don't think there's any significant advantage to the Red Line stuff to justify the cost. IMO, any Group IV/V oil of the correct viscosity should be fine.

:)

gsxr,

Very good posts. Thank you.

Have a great day,

I'm going to switch to Delvac 1 for my next change, should I go with 1k or 2k mile changes? I'll also flush the engine twice during each change. Does that sound about right?

Almost. But 500 mile changes with triple flushes in between is preferred. Oh and don't forget to sacrifice a saucer of gasoline to the diesel gods afterwards, or your pistons will melt! :eek: :p :rolleyes:

Hmm, how about the Royal Purple Synthetic oils? 15W40 and 20W50 are priced about the same (sometimes less though) as good ol' red capped Mobil 1.

Hatterasguy,

You are going to flush the engine with WATER???????? :-)

On your OM603 what are the additive levels in the sampled oil at that interval. When performing an oil analyse on my OM606.912, my soot level is still relatively low while additives are decently depleted, this was off of my last analysis a 8,086miles. How are you getting such high oil change intervals?

With continued use of Delvac at a specified oil interval of approx. 8k, would the additive content slowly increase due to the increased "cleanliness" of the engine? I also performed the EGR mod with about 1k miles after my last change so I'm curious to see how that impacts my next analysis results.

Alan Hamm sure. Ok gsxr 500 mile changes it is. I don't want to let the oil get black!

Speedy, I *think* Royal Purple is good stuff but I'm not sure. Same with Motul. It also depends what country you're buying in, as mentioned earlier.


Michael, the TBN numbers seem to be fine with either M-1 or D-1. I've been changing at ~10k for the last couple changes. Some people whined about my silicon numbers but the lab didn't throw a red flag. Here's a PDF with the data from my blue '87:

http://www.meimann.com/docs/mercedes/oil_analysis_87b.pdf

I know some people who go 15-20kmi with analysis, although IMO at that level the soot is questionable when past Mercedes' unofficial (?) 2% limit. (I say unofficial because I can't find that in print anywhere, but the MBCA Diesel Technical Advisor says it's true and I don't have reason to doubt him...)


:)

gsxr,

Your 7.5kmile to 10kmile change interval for our OM61X engines flies in the face of our board expert Larry "change your oil continuously" Bible.

Watch out, he'll be calling you an environmental extremist, a liberal, a member of the radical left, a child molesterer, etc., etc.

However, I agree with you 1000%. Finally the truth is gaining traction.

Joe
:D

I hope he isn't a priest :eek:

God damn it would you just let it go? Before you spit out any more of your "facts" you might want to read up more on Dave's oil analysis results. The 10K oil change intervals are used for his 603 engine, not the 617. He actually concluded it's safer not to go over 5000 miles on the 617. As for me I just follow what the owner's manual says. If you call that witchcraft, then I really have no further comment.

You guys are fanatical when it comes to SYNTHETIC oils..........THis is something for "THE O'RIELY FACTOR"

Just to clarify my OPINIONS... I feel that with PAO synthetic oils, 61x engines are probably safe in the 5k-7.5k range without analysis, and 60x can bump that to 7.5k-10k without analysis. I don't recommend exceeding those approximate numbers without having your specific engine oil analyzed. The analysis results for MY engines show I can go a little higher in some cases. Other people's engines can do even better. AND...

...It's also highly dependant on your driving habits! Someone who spends 95% of the time on freeway trips of 500 miles can probably go 25kmi betwen changes, as that type of service is very easy on the oil and creates almost no soot. Cold weather, cold starts, idling, low RPM, low load, etc will all increase soot, reduce oil temp, increase acids, and generally create the need to change more frequently. Synthetics can deal with this better than dino, hence the longer interval (even in 'severe service' conditions.)

IIRC, the owner's manual states somewhere around 7.5k for normal use, or 3k under severe service? And that's for plain old dino oil. I do agree that if you're using dino oil in a turbocharged engine (including MB turbodiesels), changing often is a very good idea.

:cool: