[landyacht]

Sounds like you have the 5.4L V8.

Cleaning the fuel injectors is probably a good idea one way or the other. The only thing you can really do to lower gas mileage is to drive conservatively.

These engines have up and down results. Fuel mileage depends on how you drive, the kind of roads (how flat/hilly the surounding area is), the amount of moisture/humidity where you live, your distance from sea level.

I know guys that i sold these trucks to that are getting 18-19mpg with a tent trailer on the back cruising at 100km/h down the highway. I know other guys that have them dry and are only getting 14mpg on the highway doing the same speed.

Again, the biggest factor is how you drive it but you have to consider all the variables aswell.