Oil Change

[RicM]

I'm about to do my first oil change ( a little late, already 70 hours this season). The book just says 15-40W CD spec. Any suggestions as to brand? I hear a lot about "Rotella" Premium and Synthetic. Any thoughts?

[Pitou]

Way to use that boat Ric !
Myself and most of the guys around the docks I wander use the 15w - 40 Rotella T multi-grade w/ soot control. A few use the synthetic oils.
Remember, I'm a Cummins guy so my maintenance schedule may be different than the Yanmar. Cummins schedule is to change the oil and filter every 300 hrs. or 12 months. I was told by my Cummins dealer not to use the synthetics until I reach 700 hours. Why ? I can't recall. I'm not their yet and will probably continue to use the Rotella "T" multi-grade.

[TD]

Another opinion. I have twin 370hp Cummins and prefer 15W-40 delo 400. I can use in my ZF transmissions also. I put about 150hours/year so far and change every fall. I believe delo smokes less, but it may be my imagination and I get a the best price at Costco.

[chiefrcd]

I'm a believer in synthetics, just seen too many reports and test over the years that makes me believe that they offer more protection from corrosion and heat than dino oils. I might be wrong, there is a lot of debate, but I've come to this conclusion. I try to do all the things that will prolong that $26,000.00 investment in my engine. I keep it flushed out, keep the anti-freeze balanced and changed every two years, keep it clean on the outside and try to run the best fuel in it I can......and I put in Amsoil Synthetic Marine Diesel Oil. It might not be any better than any other oil or synthetic oil, but it makes ME feel good... I do change my oil every fall or every 100 hours which ever comes first.

The last thing I'll add is this. I have a Yanmar that was built in 1999, I had to have the after market valve seals kit put in due to the "bad" seal and sticking valve issue. When they pulled my valve cover off after I'd been using Amsoil for over a year, the entire inside of the cover, all the rocker arms and mechanisims looked like they were brand new, there was no gunk, no varnish nothing....and I know several other folks who had the same work done and said that their valve covers and those same parts were gummy and varnished up. Have no idea what the difference was except they were running dino oils and I was running synthetic.

[fairtide]

HANG M' HIGH responded re oil changes that he uses 15W-40 engine oil in his ZF transmission as well as his engine. I was under the impression that these marine gears needed ATF rather than engine oil. My ZF 63A has a filter (asked about this in another post) and it is likely that a heavier oil than AFT might not be compatible with that filter. Any comments from ZF owners?

[Mariner]

I use Delo 400. Considered the synthetic variety, but Cat actually doesn't recommend it, so didn't go that route. I do, however, use Mobil 1 in my truck.

[TD]

Fairtide--I put a post on the fluid in the maintenance portion of the forum. Sorry about that.