No help for you I know, but I love my 36 gallon tank in my F150..:)
My old F150 had a 25 gallon tank, so I know the 200 mile gas stops for sure!
I can now make it to each of our favorite camping destinations without having to get gas along the way! I always had to stop at least once with the 97.
I still try to stop about every 2 hours. My wife needs to stretch after sitting for 2 hours, but at least now, it's just rest areas!
One thing I noticed is that even with 3.73 gears, if it's 'lugging' in 6th gear, I find I have to press the gas pedal a little bit more to hold speed. If I go into 5th, the rpms raise, but I don't have to press on the pedal as much to hold speed.
So, if I'm running into the wind, I'll shift into 5th and it just seems to do better.. It's no huge difference in mpgs.. I still only get around 10 mpg no matter what.. But, the truck seems to like it not lugging as much.
Good luck!
Mitch