As a first time diesel owner, I'd like to know when/what intervals the oil/filter change is needed. Also I noticed in the owners handbook, that we're supposed to drain the water from the fuel/water separator on a monthly basis? I have the extended service plan and dodge pays for all the maintenance so I just need to know when I should be taking it in to the for service. Love the diesel power, just need to change my thinking from all these years of gasoline engines.....