Starting a pool.......
 

I started a mpg test of my 6.0 diesel/automatic regular cab 4x4 F350 today. Here are the mods:

235/85 16 tires, broken in about 500 miles, replacing 265/75 16.
Radiator grill block (fabric)
Bed cover (plywood)
Removed spare tire from beneath truck and put in truck bed.
Relocated trailer harness out of airstream.

I'm driving several hundred miles on the highway in the next few days. I plan to obey the speed limits, mostly 65 mph. Just to see who pays attention to my posts, I'll send a crisp $10 bill to the person who guesses my mileage most closely. In case of a tie, the first person to post a guess wins.

21.2 mpg! :D

19.8 mpg

65mph in a Ford F-350??? (granted it's a diesel) I'm going to go with 16.8 mpg... so prove me wrong Sludgy!

What will be the shape of the bed cover? Flat, rectangular, or tapered? This makes a huge difference.

omgwtfbyobbq is hoping for a tie as he's the "first person to post a guess". He can win if his guess is the closest or he can win if others tie for closest.
We know what you meant to write...

17.6

18.1

17.5

I go for 18mpg.