I am looking for optimal maintenance procedures for a NH TC-45D. It has 275 hours already. I have the both the NH Oil Filter for $8.99 and the Walmart ST16/Fram PH16 cross reference for $2.04. I am using Delvac 1 (Mobil 5W-40W synthetic) and plan on 50 or 75 hour oil changes. Anyone have any thoughts on maintenance routines. I am a former Mech commander used to owning the maintenance on a battalion of M2/M3 Bradley diesels, and M1 Abrams turbines and the wife is a former Army helicopter attack pilot/maintainer so we are a bit strict about OCI's and maintenance procedures.