Engine oil recommendations for our old cars - Page 2 - PeachParts Mercedes-Benz Forum

JamesDean · #16 07-29-2012, 11:14 PM

Quote:

Originally Posted by vstech

isn't T6 the blue bottle 5w40 synthetic?

I think you're right. I think it is.

E150GT · #17 07-30-2012, 12:33 AM

Im gonna try T6 this go around,

Air&Road · #18 07-30-2012, 07:58 AM

Thanks for posting the table. Very interesting to peruse.

To start with, it seems that we can just ignore the top part of the table, because I understand it, CI-4 is generally no longer available.

Getting down to the oils available today, which are conveniently shaded in blue at the bottom, Delo has the highest Zinc content. Given that all the oils are really good, the highest zinc content is the decision maker for me, in spite of a slightly lower Total Base Number.

I've used Delo almost exclusively in diesels and older vehicles for over 20 years and the table seems to support my choice. This is not to say that the others are not good choices.

My $0.02,

Air&Road · #19 07-30-2012, 08:03 AM

Quote:

Originally Posted by Brian Carlton

The bottom line is that it hardly matters. Oil deteriorates over time and you can use any oil you wish if you change it on a regular basis. A diesel engine accumulates soot in the oil which is cumulative depending on hours of use. This soot is what drives the oil change well before the oil deteriorates to the point of necessitating change.

A group IV synthetic oil will protect the engine for 15K miles. However, the accumulated soot will demand that it be replaced much sooner than this mileage interval.

Accordingly, what specific diesel rated oil you select is irrelevant in the grand scheme of things.

Changing regularly is definitely the key. None of the oils in the chart are good choices if not changed on an adequately frequent basis. As to what constitutes "adequately frequent?" I won't start that war here.

ytmtnman · #20 07-30-2012, 08:44 AM

Quote:

Originally Posted by Air&Road

Changing regularly is definitely the key. None of the oils in the chart are good choices if not changed on an adequately frequent basis. As to what constitutes "adequately frequent?" I won't start that war here.

maybe this discussion could occur without a war. I for one would like to hear input.

JamesDean · #21 07-30-2012, 08:51 AM

Quote:

Originally Posted by ytmtnman

maybe this discussion could occur without a war. I for one would like to hear input.

Well here's my take on the topic:

I used to do the change every 3,000. Then I decided well you know, 5,000 is good, then I switched to some synthetics and said 7,500 will do..

Then I decided I'd send in a sample from my one 300SD and 420SEL to Blackstone Labs for oil analysis just to see what they said. I was going to run 7,500 on both cars.

The results came back for both cars. The SD was in good shape, they said go to 8,000 miles.

The 420SEL was not in such good shape, it was showing high metals in the oil, they said go to 5,000 and re-submit a sample to see how its doing..

So with that said, my approach is perform engine oil analysis to determine optimal interval. Less is always better from the stand point of the engine however the wallet will not enjoy it. If the reports from Blackstone (or any other oil lab) come back positive, I would go a 2-3 changes and send in a sample for examination..

DeliveryValve · #22 07-31-2012, 02:15 PM

Quote:

Originally Posted by JamesDean

Well here's my take on the topic:

I used to do the change every 3,000. Then I decided well you know, 5,000 is good, then I switched to some synthetics and said 7,500 will do..

Then I decided I'd send in a sample from my one 300SD and 420SEL to Blackstone Labs for oil analysis just to see what they said. I was going to run 7,500 on both cars.

The results came back for both cars. The SD was in good shape, they said go to 8,000 miles.
...

Can you post your SD's report? 8,000 miles or a bit more is right on target.

.

Air&Road · #23 07-31-2012, 02:29 PM

Quote:

Originally Posted by ytmtnman

maybe this discussion could occur without a war. I for one would like to hear input.

I will leave this discussion for others. I get into enough trouble on OD. This war will have to do without this soldier.

I have first hand experience with about 800,000 miles of operating 123 diesels, taking one of them to the 500,000 mile mark. I'm convinced that my hot, frequent changes did not hinder engine life. If I post the OCI that I used, however, I will suffer brutal attack, so I must pass.

JamesDean · #24 07-31-2012, 03:06 PM

Quote:

Originally Posted by DeliveryValve

Can you post your SD's report? 8,000 miles or a bit more is right on target.

Here you go!

E150GT · #25 07-31-2012, 03:24 PM

where would soot show up as?

DeliveryValve · #26 07-31-2012, 03:35 PM

Quote:

Originally Posted by JamesDean

Here you go!

I think you have a great report. I would like to have a TBN done though. But from appearances it looks like you have plenty of life left on this oil.

BTW - this isn't Delo 15 w40.. I though you were using T6 from your previous post.

Quote:

Originally Posted by E150GT

where would soot show up as?

Under "Insolubles"

He's doing awesome here.

For me, I think 2 would be max.

.

JamesDean · #27 07-31-2012, 03:36 PM

Quote:

Originally Posted by E150GT

where would soot show up as?

That is an excellent question, I just shot an email off to one of the guys at Blackstone, I'll post his response.. I would guess it would show up in a number of different place as its composed of different elements..

JamesDean · #28 07-31-2012, 03:38 PM

Quote:

Originally Posted by DeliveryValve

I think you have a great report. I would like to have a TBN done though. But from appearances it looks like you have plenty of life left on this oil.

BTW - this isn't Delo 15 w40.. I though you were using T6 from your previous post.

Thanks! This was the oil change just before switching to T6. I'll run the T6 to 8,000 miles, change and run another 8,000 before sending in another sample.

DeliveryValve · #29 07-31-2012, 05:14 PM

Quote:

Originally Posted by JamesDean

Thanks! This was the oil change just before switching to T6. I'll run the T6 to 8,000 miles, change and run another 8,000 before sending in another sample.

Again the looks of it, this is a great report aside from the noted higher Potassium level and lack of TBN. And this being a Conventional 15w40 oil on almost 7,500 miles.

I would bet on your engine, with keeping an eye on the Potassium, you could run T6 easily to 10,000 miles. But another oil analysis would be a wise choice to do so before hand.

.

E150GT · #30 07-31-2012, 05:27 PM

my OM617 showed high bearing wear after only 2k miles..