20-21mpg, really? The best I can get out of my 06 F350 (with 6.0) is 17 at 65 MPG. I have been averaging 15 for mixed driving. I only got 10 pulling my 31' travel trailer. I was hoping for more like 20 hwy, and 12-13 towing (which is what the 7.3 is supposed to get).

Did you delete the EGR on your truck?

Other mods?

Thanks,
Jay