If you start running a higher tune while heavy towing (more than 8-10K), the cylinder pressures will raise and you will be at a higher risk of creating a viewing window to a piston in action. Ultimately, your right foot is the biggest method of control. I have read where some guys are running the performance tune towing 20K for the last 80K miles. It is possible, as long as YOU control when you apply additional throttle during the RPM range. Probably the largest risk is when your employees drive it and might have less self-control.

These factory numbers are not at the rear wheels, just FYI. If I remember correctly, the RWHP numbers are about 15-20% less??? With the right tune, intake and exhaust, the '11-'14s run out of air and fuel at about 475HP at the rear wheels. The '15s run out around 525HP.

To all the naysayers, one thing that has not been mentioned yet is the fact that not only is the tuning changing, but the airflow has changed as well. He has not said if he has changed intakes or not, but if he is running deleted, the DPF is gone and was replaced with a much more open exhaust. I'm not an expert on anything, but higher airflow rates plus more fuel when applied to move the same load will move it faster. If not faster, then at the same speed with less fuel and air than it did when stock. It has been proven over and over that an unloaded deleted truck will net higher than stock MPGs on the highest tune level under most normal (not dragging from light to light) driving conditions. There are some guys street testing and pulling dyno and drag runs on these trucks proving these thoughts.

 

Remember we are talking about a boosted engine,,, NOT a NA engine, massive difference in performance when the boost can be correctly adjusted...
And unlike a super charger, a turbo is more or less free H/P from the otherwise wasted exhaust gases.

Here ya go...
Hows this for a great TQ curve...?

 

Interesting numbers... Noted the 3 month gap in the one test... Some 120 hp difference just in removing the DPF? That's huge!

One of the issues I have with chassis dynos is that you still don't normally get all the numbers you need, but you do get a pretty good idea in terms of what it's putting down..

One of the things I always look for are the BSFC numbers and coolant temp numbers to see where they are at in the peak torque...

While this is geared toward a gasser, the same rules of physics hold true for oilers...
How to confirm your dyno results with easy and simple calculations

So while we are increasing the volumetric efficiency, we are still going to burn proportionaly more fuel (along with air) at those peak numbers..

 

Ok I have a SCT X4 with custom tunes I got from Rudys diesel. My truck overall runs best on "Level 2". I was getting 14 mpg mixed before on "Level 1". I swapped over to level 2 over the weekend. Im now getting 17.7 mpg. This is all off of the lie-o-meter which I reset evey tank filling. Just refilled today and got 592 miles and took 34 gallons to fill which is 17.41 mpg hand calculated. So the computers off but not alot. I ran level 1 for months before this change. Everytime it was 14-14.8 mpg mixed on the lie-o-meter. This is the only change that has happened. I ran level 2 last fall and also felt like it was a ton better overall. I just never thought about swapping back to 2 until friday
From the ebay add. "Level 2 Street +72 hp and +190 ft-lbs"

 

You and others seem confused with VE. Let me make a simple example...

Yes, at wot and much higher Hp level, the engine will use more fuel.

But, at 3/4 throttle, making the same Hp that the bone stock motor makes at wide open full throttle, the engine uses less fuel to make the same HP.

So the engine is more efficient, and actually use less fuel to make similar HP levels as the oem engine.

So, pulling up that long steep grade with a 10,000lb trailer, the oem engine might be at 2/3 throttle, and the tuned truck at half throttle to go the same speed, thus using less fuel.

The above is just a fictional example, not an exact throttle position/hp ratio. Just to give you an idea of VE as it relates to us in the real world. Less throttle to do the same work. Like I said before, this applies for a clean efficient tune, not a drag race wot tune.

jmo