I am averaging 20-21 since I started driving very conservatively (I keep it below 65 on the highway), check my tires every week and keep them at 35lbs, removed the basket and air dam from the roof rack and removed about 100 lbs of stuff from the truck.

I also removed the rear seat cushions and folded the rear seat backs flat since I am usually the only occupant.

I have pretty close to 7000 miles on the truck.

I don't have a trip computer so I calculate miles between fillups divided by the gallons.