Re: "Shifting" the PowerStroke
There's no need to shift above 2500rpm unless you're towing and need the pulling power. With the low end torque I'd shift around 1800-2000rpm and that'll put your next gear down to around 1200-1400rpm which is plenty to keep going without having to worry about engine lug and heating up the transmission. On a level surface with no load or trailer you can cruise at 1000rpm easily to get the best mileage. I had a Cummins 5.9L that I used for work occasionally with the old 5 speed. PS 7.3/6.0L are similar in torque & rpm peaks.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!