I see that thread. If you slow down to 55-60 hwy, don't race stop light to stop light and shift between 1800 - 2000, (or better yet progressive shift as needed), I bet you could gain 2-3 mpg.
20 mpg might be a tough one for a truck with no overdrive but I'd say 17 - 18 is realistic given you're already over 15.
Price per barrel of crude went up $11 friday, that's $0.20 per gallon of crude. I went ahead and slammed my tanks full friday while it was still $4.69 a gallon and hadn't gone up yet around here..... Cashier and everybody in the store about S--t when I stopped at $550.00 worth of fuel in a pickup truck
Good news is my pay rates were adjusted up about another 7 cents per mile so I'm all packed and ready to leave the house early tomorrow morning. Just dispatched myself on a lightweight 29' travel trailer going to Grande Prairie, Alberta that pays very nicely