diesel oil Ok for merc 3.0?

[jmarines]

Hey guys... new to boating so please forgive me for my noob questions. I just purchased a fix her upper 95 sea ray 175 with a 3.0 i4 mercruiser. I have no history on the boat so I'm going through it making sure it's all good to go. My question is... I'm aware the proper motor oil to use is the merc/quicksilver .. but considering none of the box stores local to me carries it I am looking into other options. I've read that alot of people have had great results with delo 400. Is there a difference between the delo 400 and delo 400le?

 

[James D. Evans]

I'm running Rotella 15w-40 in my 84 3.0 with no problems. May notice a little drop in start up oil pressure, but once it warms up should be about the same as Mercruiser. This thread will prob start the great oil debate...some will say only use Mercruiser oil, others will have there brand/type that they swear by. I say pick one and go with it.

As long as it has an API service rating of SH, CF/CF-2, it'll be alright.

Use a quality oil filter, ie not a Fram. I use AC Delcos, Quicksilvers, Napa Gold, etc.

Mine will prob get Delo on its next oil change, as I am switching the truck from Rotella. I usually have enough left over in a 5 gallon after changing the truck to change the boat.

Delo 400LE is synthetic.
Delo 400 is conventional.

It's a "to each there own" principal.

 

[DaboatnutinWA]

Ive heard that the Rotella has a bit more zinc in it versus oil for cars and its good for flat tappet cam engines. I ran it in my Ford 400 for a long time with great results. Better oil pressure and quieter valvetrain. Opinions vary on the oil issue.

 

[jmarines]

Just looked over the delo 400le 15w-40
API compatible with CJ4,CI4,CI4 PLUS, CH4,SM ,SL and all prior categories . Would our type fall under the "prior catagories" ?

 

[johnzonh]

Ran rotella 15 40 last year after gasket changes No problems. Had it sitting around after we sold a diesel car