I have a question for those with deletes. How did your truck respond to the deletes while towing? I'm sure it is a lot more snappy but does it pull better? I guess I'm looking at torque increase, not just horsepower.

I have an '06 with a Smarty and it's a blast to drive. Real snappy and fun, a great daily driver. My stock '12 is sluggish and boring to drive; but, the '12 will outpull the '06 hands down. It is not even a competition.

 

I found that doing the delete, that the truck pulled my trailer better than it did stock. Typically I tow in stock mode and shift down from 6th into 5th gear on the hills. I have 3.73 gears and run 33 in tires. The truck towed better on the stock tires than my current tires.

To quantify how much better, I saw slightly better than stock but my truck wasn't stock for too long. The first year I owned the 2010 only used the truck to tow with and only put on 10000 miles. Half of them those miles was deleted.

The best part about doing the delete was the significant improvement in fuel mileage, but then again any new cummins don't really get decent fuel mileage till after the second or third oil change.

I typically drive around on mild and run an old H&S tune on my blackmax. I also run the stock timing, as the H&S tune that I run doesn't adjust timing. Heard way to many guys blowing head gaskets with tons of timing. I've also cranked my stock head bolts up 135 ft*lbs, in 125, 130 and 135 increments. I also lashed my valves at 10thou intake and 20thou exhaust. Found a few 4th gen trucks with head bolts that were fairly soft on the torque setting.

 

The first time I pulled my fifth wheel it was easy to feel th change. More power and better mpg. That was after my foot got light. I kept an eye on my trans temp. Not bad for the extra getty up an go!
nice very nice.

 

I was actually a bit disappointed in the towing power of my stock '11 vs my Edge EZ HO '01. Some of the interstate grades that my '01 pulled my 10.5K lb. fiver in 6th (both manual trans) I had to downshift to 5th with my '11. Did the deletes and all that has changed. The same grades now pull the same trailer in 6th with lower boost and EGTs than my '01....now I'm a happy camper!!! The only negative, if you want to call it that, is the weak clutch in the '11. It's now beginning to slip with only 34K miles on the clock. My '01 had 265,000 miles on the original clutch with no issues.