I am getting a 2019 C500S from a friend that has only 65 miles on it.  He basically bought it and used it a few times.  I am fairly sure he has done nothing with it maintenance wise.  I plan to change the oil with Maxima (30-029128 Pro Plus+ 10W-40 Synthetic oil or can I use Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil instead?   Amazon has plenty of oil filters (generic) should I use an OEM filter.

Change out the air filter with a Uni Filter NU-8503ST.

Do I need to service the diffs now?  If so what oil is recommended.

Anything else  I should be aware of that might need attention?

Riding style will ne in NEPA with mostly paved roads and some light trail riding in spring through fall.

As a side note I might add a plow - what is the best route to go with that?

I think the "initial" service is at 200 miles.

Change ....

Oil
Diff's
Tranny

And check the valve clearances.

......

I know but it is the amount of time I am concerned with.

I know from your posts I you can use 0,5,10 or 15W40 oil

Is the uni filter  NU-8503ST correct?

What weight diff oil?

Also can you point me to a thread on how to check valve clearance?

thx

15w40 or 15w50 is good for the engine.
75w90 is good for the tranny and the diffs.

https://www.youtube.com/watch?v=MPN9w6ZWSAw