Before I lifted mine I got 19-20 now I get 16-17

 

I have a 2002 4x4 scab with a 5.4 that I purchased new. I try to practice good throttle management, keeping the RPMS down, tires properly inflated, truck maintained. I figure the mpg every fillup, and I have never made over 14 mpg, usually closer to 12.5. I was considering getting a programmer, but if it won't help much, probably just spend the money on more gas.

 

Tug is right on here, although I disagree with the higher octane part. Driving it "hypermiling" style will help. That means using gravity to help accelerate down hills and then carrying that speed up the next will with a light throttle (also known as "deadfoot" or "geezer" driving), coasting up to red lights far in advance rather than charging/braking hard, avoiding full stops, putting the auto transmission in neutral at stop lights and shutting down at long stop lights, stuff like that. I do these things as a habit and am still lucky to get 20 mpg on the highway at an average speed of 70-75 mph. I could save gas by slowing down a little, but I don't want to get rear-ended. On the country roads where I live it's much easier to get 20 mpg, but that's because I can't go over 55 safely with all the twisties.

I don't know if the ECU shuts off gas to the injectors while coasting like the big diesels do. It doesn't seem to. If it did, that would help.

 

4x4 lifted.larger tires go fast = poor milage Duh.

 

you prety much sumed it up man

 

how does using 93 octane improve mpg unless it is tuned for it?

 

The 5.4 runs rough it shakes at idle I found by me running 93 in my truck the shake is gone and my truck runs very smooth at idle

 

It doesn't improve gas
Mileage it eliminates the shake at idle

 

A tuner with quality written tune will only improve gas mpg MAYBE 1 to 2 and that's only if you keep your foot out of it.

 

Heck even if a tuner can get you another mpg that is pretty good! I wouldn't expect mileage to go up towing but it should make hills easier.