One thing you may be able to try is dealing with your Static Load Diameter. Basically, the tire is designed to be 32.1 inches round.
Something you can do is measure from the center of the hub to the ground until the distance is 16 inches. You may have to air up the tire or air down the tire depending on what your starting pressure is. I have a suspicion that once you get the hubs 16 inches off the ground your MPG and noise will improve. Ride may as well.
You will need to do this empty and loaded... once you get the hubs 16 inches off the ground take a note of the PSI so you can maintain those pressure's loaded a unloaded.
Thanks!
Jeremiah
