Hi, Swan. Welcome to the forum. There are many great people here willing to help you with your car any way that they can, and a few smartasses. I belong to the latter group and sometimes to the former. You are just in time to win the Official TwitchKitty Award for Posting Without Searching First. Your prize is the knowledge that there are many, many threads about oil and related topics for you to read if you search for them. Congratulations and here's hoping that you have a long and rewarding stay here at the forum.

Never again... I have a a true Bypass filter. Just add a quart with a tp change!

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Matt (SD,CA)

1984 300SD.. White/Chrome Bunts..Green

1997 2500 Dodge Ram 5.9 Cummins 12 Valve 36 PSI of Boost = 400+hp & 800+tQ .. ..Greenspeed

2004 Dodge Ram 2500 4x4 Quad Cab Cummins 5.9 H.O "596hp/1225tq" 6 spd. Man. Leather Heated seats/Loaded..Flame Red....GREENSPEED

Global warming...Doing my part, Smokin da hippies..

Fight the good fight!......

Sorry to steal the thread for a second. Damn hattie, where are you driving? I am just at 244600. I thought you were parking that thing for a while and letting me catch up?

Been swamped lately and unable to spend time here with my buddies. Hope all is well.

Back to your regularly scheduled oil thread:

Just yesterday I put in my second round of synthetic (Mobile 1) in the SDL. I did not take a sample to have it tested. I plan to have it tested just as I beat Hattie to 250K.

Also changed the SL to synthetic. Unfortunately for my race to 250K, it is spring and SL time!. And my indy told me I HAVE to start driving it more to keep the tranny from leaking. I am begrudgingly going to comply

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Alan Hamm
'87 300SDL 277K Miles
'89 560 SL 68K Miles

Quick side track them back on topic:

How is it going Alan? If the boat floating yet?

I just have many places to go I guess! I have been pretty busy over the last few weeks. I just got back from camping and ran 250 miles on the SDL over the weekend, plus the 400 I put on it last week. 650 in a little over a week!

I am about 300 miles short of 247k and will be crossing that within a week. I think I just may beat you! It must be a pita to drive a drop top in this nice spring weather!

Back on track, oil thread yeah!

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

sorry, mr twitchkitty. i searched around for about thirty minutes trying to find an oil thread specifically about biodiesel and oil changes but was unsuccessful. maybe i just don't know how to use these new-fangled websites . . . or maybe i should just stick to more conventional means of gathering info. sorry to intrude on your site. thanks everyone for your help.

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1979 300sBd (that's Bio, baby!) - 170,000 miles

It stays in for the winter. But I have not gotten it ready for the season yet. Hoping to get down to it this coming weekend.

I am not conceding the race yet!

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Alan Hamm
'87 300SDL 277K Miles
'89 560 SL 68K Miles

Brian,

I believe that the accepted soot concentration in oil for the 617 as per MB's specs is a maximum of 2%. Of course, Amsoil's tests show that its diesel oils can keep soot well suspended at up to 10%, but I use 2% as my maximum as that's what the engine manufacturer recommends.

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1999 Mercedes-Benz S600, 103K miles - garage queen
1988 Mercedes-Benz 560SEL, 89K miles - daily driver
2007 Hyundai Sonata Limited, 31K - daily driver

Don,

Is there anything magical about 2%? How does M/B actually know what 2% soot loading will do to an engine over an extended period? I'm sure that they cannot know. So, the 2% figure is a stab in the dark based upon engine longevity.

Let's rephrase it:

How much find sand do you want in your oil? Is 2% acceptable to you or would you prefer to keep it down to 1%?

With the forum attempting to find better filters and with some going to bypass filters that can filter down to 5 microns, why would you run around with 2% soot in your oil if you could easily avoid it?

To actually give a partial answer to your specific question, Biodiesel produces about 50% less soot (depending on feedstock, amount of FFA's in the oil, etc.), so theoretically, you might get 50% more life out of your oil, but the only way to know is analysis. Do 5k miles on your oil while running biodiesel, then drop some oil for an analysis. If soot is only 1% or less, then I'd push it to 7,500 and do another analysis. Of course if soot is 4% or more, then you went too far. Change oil and do an analysis at less miles till you find your comfort zone.

You should only have to do this once with your engine to get a baseline on how it performs and to get an average soot level. After that, just do conservative changes based on your goals of acceptable soot.

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1984 300D Turbo - 4-speed manual conversion, mid-level resto

1983 300D - parts car

1979 300TD Auto - Parts car.

1985 300D Auto - Wrecked/Parts.


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"If you don't know where you are going, any road will get you there". Lewis Carrol

Brian,

You've made some good points, however just because I can't explain how MB decided on the 2% figure doesn't mean it wasn't a well researched and engineering-based figure. In fact, overall it seems like most people use 2% as the maximum soot concentration for diesels (from what I've been reading online). I can understand your example using sand, however, while I'd really prefer 0% sand, it doesn't mean that 2% is enough to cause significantly more wear/damage. Like many things, you have a very safe range to play with. 0 - 2% will probably produce similar engine wear rates. This is just my guess as I don't know this for sure. Indeed the forum members are forever busy looking for better filters, but then this forum is full of people who live to work on and improve on these cars. Many of the things we do around here are, for lack of a better phrase, excessive and unnecessary. And even when they aren't, we are yet to disprove old methods as being significantly less effective.

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1999 Mercedes-Benz S600, 103K miles - garage queen
1988 Mercedes-Benz 560SEL, 89K miles - daily driver
2007 Hyundai Sonata Limited, 31K - daily driver