Hi you all

I have a 95-E320 with 167k-km (about 100k miles), new to me. The oil question interests me. I enquired towards synthetic vrs non-synthetic at my most recent trip to the local dealer. His statement, if its been running non-synthetic, stick with it otherwise it will leak. Interesting statement.

Regarding brands, I have a ford F250 diesel that I have been using Kendel 15W-40 because with each engine oil change, they will analysis the oil for next to nothing. Can this be used in the mercedes?