[nubbzcummins]

Quick specs: 06 dodge ram 2500 4x4, 5.9l turbo diesel, 2.5" lift in front to level, 4 spd auto with o/d, cruise control, 3.73 gears, 325/55r22 tires, intake, exhaust, programmer. Tranny has 3 modes: Normal, tow/haul, and o/d off. Normal will make shifts at higher rpms and only lock t/c in o/d at lowest speed of 57mph however if cruise control is on you can maintain locked t/c as low as 1000rpm and around 41mph. Tow/haul makes shifts around 100-200rpm sooner than normal, runs higher fluid pressure in tranny, locks t/c when shifting to 3rd at 34mph and o/d at 53mph. Can go as slow as 28mph in 3rd and 49mph in o/d before the t/c will unlock. O/d off operates like normal except no o/d.

Normal driving conditions: Drive approx 140 miles/day mostly highway with some city driving and probly a dozen traffic lights to deal with. Highway has 45-55mph max and city 35mph max. Terrain is mostly slow rolling hills, some flats, and some pretty decent hils.

With a truck with around 38 sq. ft. frontal area, a fairly bad cd, and over 7000lbs driving efficiently gets tough. Best technique so far has been cruise at 50mph and coasting in neutral down hills along with timing lights and keeping speed up as much as possible as well as keeping idle time to a min. Any help will be appreciated.