First diesel tractor I have owned.
On the oil cap it reads........ Use 10W30 DS Class
Regular engine oil or oil labeled for diesels?
Thanks...........bob
Two things.
First: Shell Rotella has been a strong interest for diesel engines because it had the highest concentrations of ZDDP, which is the zinc and phosphorus content. Since the govt legislation, to reduce the ZDDP content in oil used in an emission compliant engine, Shell no longer has the highest concentration of these critical oil components for a diesel engine.
Second: I won't bore you with a long winded speach so let me suffice to say that oil weight is critical so don't use a weight different than the design the mfgr specifies because the clearances of the engine are set for that specific viscosity.
In modern oil ratings a "CF" is a high performance oil with high enough levels of the ZDDP to satisfy the demands of a diesel or high performance gas engine. Rotella T SAE 30 with a "CF" rating is super for your engine. I got some of this from NAPA for my L175.
The critical thing that the ZDDP satisfies is the metal to metal running relationship of flat tappet lifters and injection pump enviornments. Accelerated wear and premature engine failure is a given without the proper friction and scuff reducers that the zinc and phosphorus give.
ZDDP can also be added as an oil supplement but some of these supplements don't bond well and the oil will wash the additives of because they have high concentrations of cleaners also. The product that GM makes for this is perfect if you wanted to add some to your favorite oil. GM has what once was called E.O.S. (engine oil supplement) but now is known as "engine assembly lubricant" which is the exact same thing. Due to govt legislation it can not be called engine oil supplement so it is called something else and it is in a different labeled bottle of different fluid capacity. Nice trick huh.
I assemble all my engines with this GM product, incidently the new bottle has EOS on the label but no explanation for this designation,
and it can be used as an additive for diesel and high perf engines. One engine that will die fast is a flat tappet cam with high spring pressures in the head. Often the cam lobes will not survive break in due to the lack of the zinc.
Hope this helps