What oil for Yanmar engine

[trantor12020]

I've a Yanmar 2GM20F. I uses EssoMobil Delvac MX 15W40 API CH-4, CF-4 ...-4, SJ/CF grade. My engine manual states only CD grade. Do I suppose the later/higher grade covers all older ones ? I checked on Torresen's web and they sells Yanmar brand oil (p/n: 41540) with the above API CH-4, CG-4, CF-4, CF/SJ grades for use with 2GM20F (I assume since it appears in the filter page for 2GM20F).
However, when I read my friend's 3YM30 manual, it states that the YM engine should NOT use oil with CH-4, CG-4,...-4 spec as this would cause excessive wear to the valve train assembly.
Now I'm uncertain if I should continue to use -4 spec oil for my 2GM20F for fear of same wearing on my engine. Any advise appreciated.

[PBzeer]

I use Chevron Delo in my 2GM.

[theartfuldodger]

The 3ym engine meets the 2010 emissions, so reason for different oil and if you notice the injectors are on the other side another improvement for good burn, have a new yanmar in my morgan and real good on fuel.

[theartfuldodger]

I should also say that I'm a deisel mechanic, both heavy equipment and marine, love working on the yanmar its a real toy

[CalebD]

Doesn't Rotella T cover most of the Cx Sx additives? Isn't this oil one of the best available?

[theartfuldodger]

Yes is the oil of choice for sure

[billangiep]

I also use the Chevron Delo multi-grade in my 3GM. I was informed by the dealer not to use this oil in the trans. They sugested a straight 30 weight non detergent to reduce wear on the cone.
Bill,

[dvpamenter]

I use Rotella T in my 19822 GM. Diesel mechanic recommended.
Don

[theartfuldodger]

The 3gm uses a different oil then the 3ym, and yes the gear box takes a different oil then the engine, and depending on the slope of the engine, one has to be careful not to over fill gear box and cause foaming, which was something I learned the hard way but caused no damage.

[k1vsk]

These recurrent debates about lube oil seem to never end. This time I'll take the liberty of making the only important point to eventually result - that frequent changes of the oil and filter are FAR more important than what brand you choose as they are almost all essentially equivalent.