Hey Wade -
7.3L is a beast. We definitely considered the motor. Love the design and durability. Plus, the focus being on simplicity and reliability not mpg. This is the problem I see with most of the Dodge/Ram/Chrysler products (complexity for efficiency). It's all a trade off. But back on topic...
We could have ordered the 7.3L but decided against for several reasons. It's new and unproven. Not to say it won't be great but I don't want to find the issues. Many places we go are far from easy recovery or towing. There is value in a proven drivetrain. Also, the transmission is "new" and two crucial components being updated gives me pause. Cost increase is minimal. I'd buy one in 5+ years after any bugs are worked through.
MPG. This is going to be essentially the same (sadly). We are 14-15mpg mixed driving empty lifted on 37s. 10-13mpg with camper. 9-10mpg with camper and trailer in tow. I've tested higher octane but doesn't seem to make a difference. So sticking with 87 for now. 55 gallons of fuel gives us the range needed.
From a performance standpoint... the 6.2L has plenty of power. Sure the 7.3L is better. But you could also buy the 6.7L for more. Or supercharge either gasser for serious performance. More power is always enticing! Is it needed? Nope, not for us
6.2L is a basic design motor. Cast block. Aluminum heads. SOHC. 2 Valve per cylinder. But it does have the unusual 16 spark plugs. That's probably the only fault for complexity but it's been well proven. The only issue you'll hear about is the occasional lifter tap on start up (randomly occurs for a couple seconds). It likes chugging along under 2k rpm even loaded. But for max power you'll need to be in the 4k range. We rarely exceed 3k rpm even on hills and towing.
Thanks so much,, great info & insight,,, we are kind of in the same place,, even though the 7.3 has been out for a year now,, and it'll be a new vehicle under warranty,,, do we want to be the one finding a new problem,, maybe,, maybe not,, lots to consider,,
Thanks again for the info,, Wade