[THEFERMANATOR]

Thats alot of RPM's for that engine to be spinning. I would think f all was well, it should still get mid to high teens for milage. The 7.3L is a bit of a dog, but was known to pull alot of weight(slowly, but would maintain speed on some steep inclines), and get good milage. I believe many upgrade the tuning and go to a different stryle of injector to get a good boost in power and economy. If your looking for to much out of it, you're going to need to intercool it. Theres no intercooler on that engine from the factory, and it really hurts them. Also make sure your high pressure oil crossover is good, and consider flushing out the HPOP reservoir. Theres a guy on youtube with ALOT of GOOD powerstroke videos that lists off alot of things to check and do to them. And give DPTUNER a call for tuning as he is considered about the best for 7.3's.