2 days is 216 miles then, I used to drive 62 miles, 4x a week, thats....248 miles, so I guess that seems normal, but I was getting 21mpg and still had 1/4 left or a bit more at the end of the week after going more miles. No mods on your truck? What engines in it? Could be you have a smaller tank than I did.
I worked on a Ranger that actually had 2 fuel tanks factory installed, it was an 88 or 89 i think..I'm not sure what year they stopped that, what year is your truck? You could always rig a second gas tank into the bed, make sure its super secure, and then make some sort of a little valve system so that when your primary tank gets low, you can just open up a valve and the gas from the external tank fills up the primary one again.
'12 GMC Sierra 1500 | 4.8L | Auto | 4 wheel drive | Bone stock