I just bought an 08 King Ranch with the 6.4 PSD. A previous owner had already gotten rid of the cat and dpf. It has an AFE CAI and SCT touch screen xtreme tuner. It is loaded with a custom tune that is named 250HP. The box for the tuner has ALLOUT OFFROAD written on the box. This is my first diesel so I am trying to figure out what all has been done to the truck. I LOVE IT SO FAR. I bought the truck because I am moving and will be making multiple 3 hour trips towing a 20 ft covered car hauler loaded with stuff. Probably 10K lbs max. Should I return the truck to stock tune before pulling the fully loaded trailer? There is also the preloaded tune from SCT. or just keep the one called 250HP loaded??

 

Tough call. I have towed that heavy with my 275hp file, but it was all interstate. Mostly tow stock, but if I ever have a good long highway run, I'll tow tuned. Crazy thing is that I run cooler EGTs and coolant temps and use half the boost towing with the big tunes compared to stock, but I tow stock most of the time for the transmission's sake.

 

As a rule I tow <10K with some tuning.
>10K in stock power.

Tranny feels better to me that way.

In addition, that is what the engineers designed into the drive train imho.

 

I run Spartans 210 tow tune all the time, towing or not. I'm not a big fan of switching tunes around all the time.

Something to remember is that just because you have all that power on tap does not mean you have to use it. I drive and tow the same way I did stock, IE like a granny, and my engine parameters stay within the same limits tuned they stayed within when I towed stock. Tuned you might be able to pull 20k up a 13% grade at 75 and climbing, but you don't have to, and if you tried you'd probably be changing parts soon.

Personally I see no issues towing with a bigger tune, as long as you drive like you've got some sense. Your right foot determines how hard you push your engine, not the tune in the box.

 

I tow over 25k with my Spartan 210 NON towing tune almost daily.....