I just got my 7.3, and it's my first diesel. I've been looking for input on tuners as well. Seems to be Hydra and GH is the way to go. Now, would this be okay for a bone stock 7.3? or should I upgrade the Intake and do a 4in. Turbo back straight pipe? It's also my understanding that I should get a gauge column with at least EGT, Boost, and Trans Temp, correct?

 

I'm interested in answers to this as well. Also can someone tell me what kind of mileage improvements they have experienced?

 

Zero. Nothing. Nada. If fuel economy is your goal, the stock tuning pretty much nailed it. I'm not saying your economy will get worse with a tune, but you can't expect better. The best thing you can do for good fuel economy is in this order:

1. Make sure the truck is 100%. No slipping torque converter, no plugged air filters, no dragging brakes, and no failed sensors.
2. Make sure your odometer is accurate. Many people with lifts and big tires immediately complain that their economy went to hell. Well... 40" tires mess with the reported miles traveled, which is half of the fuel economy math.
3. Install a block of wood under the throttle. I jest ever so slightly, but your right foot's attitude has a profound impact on economy.
4. The lift, while cool looking to some, makes our 8000 pound brick a tall 8000 pound brick. What happens when you try to push a 4' by 8' sheet of plywood flat against the wind vs a 2" by 4" stud?

 

I not trying to be disagreeable with the following question (because you're much more of an expert than I) but others that I've talked to have told me there is an improvement and they explain that changing the parameters depending on if you're towing vs non-towing for instance makes a difference. Can you comment on that? Trying to understand.

 

Simple answer:

Power comes from fuel. If it takes x amount of fuel to maintain a specific speed with a certain load, it's going to take the same amount of fuel regardless of what the person who wrote the tuning does. Oftentimes the consumption goes up because there is more power on tap; the load is pulled faster up grades and into headwinds. Towing-specific tunes usually hold the gears (higher upshift speeds) longer too....hard to save fuel with higher engine RPM.

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Cody can say it better than just about anybody, because he's a tuner of a very high caliber. I come at it from the aspect of poring over Megabytes of performance data from dozens of trucks, including dozens of tunes on several platforms on my own personal vehicle. Like Cody said, it takes xyz fuel to generate enough power to sustain 60, 65, or 70 MPH on the flat with no wind - with the torque converter locked and nothing dragging. The only thing tuning can really change at this point is to tinker with the transmission to lower the MPG empty, or to help the engine to handle a heavier load under specific conditions (like grades or headwinds).

When towing, the brass ring isn't better fuel economy per se - it's lower Exhaust Gas Temperatures and Transmission Fluid Temperature. Fat good it does to extend the distance between pumps if you never make it there because of a smoked transmission or engine.