dealer told me every 3,000miles with the new 600, is this true?

 

No. The owners manual says 7500 miles for extreem use and 15000 for light duty. Most people go with the 7500 mile schedule. I change mine around 6000.

 

I've got 3300 miles on my truck and will change the oil every 5000 miles.

 

Your 1st oil change should be done right away. 3,000 is the max on the 1st one. You can stretch it out to 7,500 after that. What is the point is waiting?

 

California trucks show a 3k maintenance interval due to emisions. All others show a 7500k interval. Even on my 01 I go 7K +.

 

First change @ 7500 coming up on 20k now going to do an oil analysis tomorrow before 2nd change at 22k. I picked up the Cummins manual and they recommend 15k oil changes for normal use (for diesel) engines. If I remember right right you need to be down somewhere around 10miles/hour average before lowering to the 7.5k interval.