[cons]

Thanks for the input Aerohead. I've just driven cross-country and have a great idea on what the truck gets with all my life's load in the back and in the cab. I'm guessing it's around 700 pounds. Don't know how much of an effect that should result in.
The first day, there was no wind, got 39 mpg on 15.7 gallons, usually going 60-75 mph, but had a slow construction zone for an hour. Went from 6,200 ft-4,000 ft
2nd day, 15.5 gallons, removed grill block due to it being a hot day and big load, got 34 mpg, at 65-75 mph, down to 2,000 ft.
3rd day, 14.3 gallons, 37.5 mpg, did the grill block for the second half, crazy cross wind, down to sea level
Then went 75 mph purely for 4 gallons, got 22.7 mpg, bad crosswind, hard rain, lights
Then purely 60, needed headlights, wipers high speed due to hard rain, bad crosswind, 37.1 mpg, that difference seems too big.
4th day, 14.9 gallons, 34.7 mpg, very stiff head wind all day, constantly watching the flags to verify that direction. It sucks, I only had a tail wind for a couple hours on the second day! And I went from west to east!

These were not ideal conditions (warm and calm would've been great). Also huge load (I'll put pics up soon). So to be getting 37 in it wasn't a big disappointment. But I'm still really curious on those 60 mpg runs.

Did some coast down testing in Jackson before the trip and used the tool here for that. Seemed to be around .24 to .26 on the graph. Factory is .49

My tires are at 38-40 psi (max is 44), might have gotten lower due to the colder temps and coming down from the higher altitude. I don't know how much that would effect the long drive. Also, the load in Odd is so heavy the boat tail is at least a foot lower than it was pre-load. That might have thrown off my angles a little. Going on a sailing trip for the next month and might not get in a good long highway run to see how Odd does, empty, at sea level. But I might be too damn curious and have to try anyway.

People at the pump were always stoked to see Odd, and I direct them all to this site. Cheers to this site!