Same here. Have you actually ever filled up more than 23 gallons?That stinks. Checked my Laramie(non-etorque) through your link and it's 26.
Is it a space issue? Etorq trucks can option for the 33 gallon tank?
I've gotten it down to 1/8th of a tank (50 miles to empty) and only ever get 20 gallons during fill up. I'm going to try to run it down to around 5 miles to empty this week and try again.