trying to research used prostar isx15 best atm, tc10 or ultrashift?

[Rawze]

Unless someone has a specific need for an auto-s$itter tranny, then your better off in the long run with a manual tranny for a truck. Auto-trannies are inherently about 0.6 mpg less fuel efficient than a decent driver.. and as well, they have a lot higher maint costs over time. Auto trannies also will lug the engine to death, it is hard to make one rev the engine above 1500+ in a hard pull like it should be doing. They tend to always try to minimize RPM on the engine and this shortens the life of the engine by quite a bit over time.