oil change

[rappareems]

I have always used 30 weight oil for my M25 diesel.... I seem to recall some suggestions for something new... I would welcome suggestions.  Going to do the pre haul maintenance in a couple weeks.

Mark

[chuck53]

15w-40

[Dave Spencer]

Mark,
I too use 15W40.  I always use Shell Rotella oil for some reason. 

[Ron Hill]

Mark : Straight 30W is what Kubota recommends for your M25 1986 engine.  

15W40 is what most of the synthetic diesel oil is now.

Your choice

[Jeff Kaplan]

Mark, I have always used Chevron Delo400  30W , perfect for our short seasons. Stay with the 30W, don't need a multi viscosity oil unless you sail all year, then a 10W-30 or 15W-40 would work.

[KWKloeber]

I have always used 30 weight oil for my M25 diesel.... I seem to recall some suggestions for something new... I would welcome suggestions.

Mark

See the TechWiki under engines > mechanical  - and oil recommendation.

I have an tech paper that shows excessive wear on diesels that use synthetic oil.  Why chance it?  Go Dino.  Rotella is perfect.
She's yours -- so your choice.
I'll post the info if I can locate the PDF.  CRS.

kk

[kwaltersmi]

FWIW, the Universal operator's manual specifies 15W40. I use Shell Rotella T 15W40.

[Les Luzar]

I use Delo 400 SAE 30 that I bought at the Captain's Locker, Marine Store. I noticed that it is API CF. CF is for older Diesels. At Walmart the Delo 400LE is SAE 15W-40.  API CJ-4/SM. It says that this is for newer Diesel engines. What is the API for Rotella? And does anyone know if this API difference CJ-4/SM vs API CF makes a difference? I am inclined to stick with my Delo 400 CF. Any thoughts?

[Stu Jackson]

Les, they are always "improving" the formulas for motor oils, for both gasoline & diesel engines.  The diesel ratings letter designations have been moving higher in the alphabet over time.  I just did a quick wikipedia search on "motor oil" - try it, it explains it all.

Your Delo is just fine.