Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

[Scubaseas]

I have 2 brand new Yanmar 4JH57CR engines being installed in my cat. I’m keen on using synthetic. Thoughts? __________________

Doug

Not to speak for Jim either but you should use the oil that the manufacturer says you should use. 15W-40 (-15 to 40C) or 10W30 (-20 to 30C) is what is in your manual. If you don't use that viscosity and meet the "C" spec (or above, I doubt you can even find some of the C oils listed in the manual anymore) you may void the warranty. No problem using synthetic but do not exceed the change intervals.

Al
ASE Master Mechanic

[Divedoug68]

Originally Posted by Scubaseas

Doug

Not to speak for Jim either but you should use the oil that the manufacturer says you should use. 15W-40 (-15 to 40C) or 10W30 (-20 to 30C) is what is in your manual. If you don't use that viscosity and meet the "C" spec (or above, I doubt you can even find some of the C oils listed in the manual anymore) you may void the warranty. No problem using synthetic but do not exceed the change intervals.

Al
ASE Master Mechanic

Thanks, that is the plan. Use the synthetic T6 15W-40 and still change the oil at the prescribed intervals. I’ll drain the oil that shipped with the engines and replace with the Shell Rotella. Thanks for the advice/confirmation.

[Wotname]

Originally Posted by Scubaseas

........ If you don't use that viscosity and meet the "C" spec (or above, I doubt you can even find some of the C oils listed in the manual anymore) you may void the warranty. .........

Also not speaking for Jim .

Most likely the lowest C spec listed in the Yanmar manual is CD and that is available if you go looking for it (usually as single weight SAE30). Just not available in many Auto stores, you have to look in small engine shops e.g. Briggs and Stratton places etc.

I'm not suggesting you should (or shouldn't) use an CD oil but it is available contrary to much internet myth.

[Scubaseas]

I’ll drain the oil that shipped with the engines and replace with the Shell Rotella.

I would get and read the manual and follow the break in procedure religiously. I would not change the oil they shipped the motor with. The oil when you get it may have a higher zinc content and maybe a break in type oil. If Yanmar wanted you to change the oil before running they would tell you.

Most likely the lowest C spec listed in the Yanmar manual is CD and that is available if you go looking for it (usually as single weight SAE30).

Very true. While the manual says CD or higher is fine they state the recommended viscosity is 10w-30 or 15w-40. Finding a CD oil in multi vis may be near impossible. Rotella T6 is a CK-4 oil and the motor he has is modern, common rail and low emission. For low sulphur fuel like today (as opposed to high sulphur or 30 years ago) works better with higher grades than CD. Like CK-4 which is fine for the application, easily had and what the owner wants. https://dieselnet.com/tech/lube_clas...tions.php#ck-4

As they are new engines there is a warranty to consider and it would be wise to use and operate the motors exactly the way the Factory tells you. With all due respect to Mr. Bunyard I would think Yanmar would be the authority on what to use in regards to lubricants.

Don't forget to change the marine gear oil and adjust the valves. Keep an engine log book as it may aid in any warranty issue (save your receipts) and resale value.