On interstate - set cruse on 60 and leave it alone. State hwy's - 55 and leave it. Truck has K&N intake and chip, nothing special. Do not get into it! As I said, run in 5th gear, that way it does not up/down shift, even on the steepest grades (unless heavy headwind, then it may on a long steep grade). Couple of times we had to be at a certain place at a certain time. Went 70 and it destroyed the mph, drop like a rock to 10-11 with no headwind. So, I back off and love it. We are not in any hurry anymore, traveling all the time, so a few mph adds up quick.
Mike and Judy
Wherever we are parked is our home
2009 - 36RD5S
2007 - Dodge 3500 6.7 Cummins
May God bless