Am I changing the oil too often?

[undercutter]

Typical oil changes on the main engine are 200hrs. Shell R4 in the main engine and Shell R6 in the genset.

I have read that I could go 500 hours with these oils especially with the non egr main engine just changing the filters at 250hrs.

Input?

[donradcliffe]

And the engine is a ?HP with ?liters in the oil sump?

[undercutter]

Originally Posted by donradcliffe

And the engine is a ?HP with ?liters in the oil sump?

Main 135hp with 13 litre
Genset 30hp 3 litres

What is the significance?

[Compass790]

I wouldnt pay the $30 to read this but you may be willing to.
https://www.sae.org/publications/tec...ontent/982718/ If you do please report back.
I routinely would run synthetic oil for 20,000 miles in my car ( Done 300,000km ) but have been reluctant to do long drain intervals in the boat diesel as oil gets so black but I see many oils tout themselves as being suitable for extended drain intervals. Also our oil capacity is only about 2 litres so it's not worth worrying about but I'm curious as to what SAE study shows

[Compass790]

Sorry forgot to say it implies in the brief description of the study you can do 4x the normal drain intervals if you use a premium synthetic oil. Would need to read full study to find out I guess

[MartinR]

One of the problems is that if you have an old engine you definitely do not want to use synthetic oil. Unless it was used from the beginning. Also, I guess the study was done on trucks, not boats.

[Lepke]

The only harm to your engines from changing the oil too often is the engine will last longer because of less debris in the oil.

[GordMay]

Lubricant marketers do not set oil change intervals; these recommendations are made by the engine manufacturers. The point of using high-quality synthetic oil is to take better care of the engine and reduce deposit formation, which may reduce power, performance, and fuel economy; rather than extending the drain interval. I’d recommend following an engine’s manufacturer’s specified oil/filtre change intervals.

See also ➥ https://www.powerandmotoryacht.com/m...-older-engines

[undercutter]

Originally Posted by MartinR

One of the problems is that if you have an old engine you definitely do not want to use synthetic oil. Unless it was used from the beginning. Also, I guess the study was done on trucks, not boats.

Any links to that study? I had an electric driven gear box that ran 10w40 oil and would seize after 030 seconds of operation. Replaced oil with straight synthetic and it never quit again. Amazing stuff.

[undercutter]

Originally Posted by GordMay

Lubricant marketers do not set oil change intervals; these recommendations are made by the engine manufacturers. The point of using high-quality synthetic oil is to take better care of the engine and reduce deposit formation, which may reduce power, performance, and fuel economy; rather than extending the drain interval. I’d recommend following an engine’s manufacturer’s specified oil/filtre change intervals.

See also ➥ https://www.powerandmotoryacht.com/m...-older-engines

I read that link regarding an old detroit engine. Not really a lot of information there however stated it was important the oil used met the engine manufacturers standard.

The question regarding extending oil change intervals is promoted in the attachment from shell that I uploaded. Of course I would continue to change the filters as recommended.

[undercutter]

Here is the pdf file from Shell.

[Compass790]

Originally Posted by undercutter

Any links to that study? I had an electric driven gear box that ran 10w40 oil and would seize after 030 seconds of operation. Replaced oil with straight synthetic and it never quit again. Amazing stuff.

I gave you the link to the study in post #4

[Dockhead]

Originally Posted by undercutter

Here is the pdf file from Shell.

That's not synthetic oil.


The extended oil change intervals in the case described in the PDF were achieved by careful and regular oil analysis.


I have never been comfortable extending oil change intervals with small marine diesels. I don't think that the oil life is limited by breakdown of the oil as much as by the accumulation of soot and acid -- in our relatively old relatively smoky engines. I feel like I'm "taking out the trash" when I change my oil, and I try not to go much over 100 hours, even though the recommended interval is 250.


As to what grade and type of oil to use -- I wouldn't deviate from the manufacturer's specifications.

[sailorboy1]

Originally Posted by undercutter

Typical oil changes on the main engine are 200hrs. Shell R4 in the main engine and Shell R6 in the genset.

I have read that I could go 500 hours with these oils especially with the non egr main engine just changing the filters at 250hrs.

Input?

Isn't the R4 the blended oil? If so why would you use that when the full synthetic is better and basically the same price? I'm using the T6 full synthetic in both my main engine and generator. I increased the interval for the main, but decreased the generator as the manual interval in it made no sense for an engine without a filter.

I think how you operate the engine is at least as important as the interval (within reason).

[Sojourner]

So tangent question: my engine was not rebuilt properly and Smokes and eats a liter of oil per 40 hours. Not getting back to repairing it till winter. Do I still need to change the oil or just the filter if I go over 200 hours before then? It's all brand new oil effectively...?