Recently Purchased a 2002 with the 5.4 engine. I'm really surprised at the low gas milage, anywhere between 9 and 12 mpg. Haven't taken a trip to check the highway mpg. She's extended cab, 4X4 FX4, Lariat, with all the bells and whistles. Am I just hoping for too much or can some changes be made as K&N,etc?

Photo:
https://www.f150online.com/galleries....cfm?gnum=8663

 

Hey fishingtrout, I also have a 2002 with the 5.4 engine but mine is a supercrew (2 wheel drive) I get 11-12 mpg in the city.
I have not changed my spark plugs nor replaced the upstream 02 sensors so you may look into that on your truck..Some people get anywhere from 13-15 on average so we are the unlucky ones I guess

 

Thanks, I had planned on changing the plugs and plug wires but hadn't thought about 02 sensors. Maybe a K&N air filter would also help, and I usually add a can of SeaFoam to a tank of gas every other month to keep injectors clean. Thanks again for the ideas.

 

I just got 245 miles on 15 gallons of gas this week, mostly highway driving. That's a little better than 16mpg. Scab, 4x4, 5.4l, 3.73 gears, 135k miles, everything stock but magnaflow exhaust.

 

That's a little low even for a 2V 5.4L. I get almost 15 MPG in my stock 5.4L SCrew in 50/50 driving. My first guess for your low MPG would be your driving habits. Keep the RPM's below 1800 when accelerating, coast to a stop, don't romp on it at lights, etc... will make a huge difference in these rather heavy trucks.

You don't need to use fuel injector cleaners. Not only are they not necessary, they'll rob you 1-3 MPG.

 

Please explain?

 

I'm pretty easy on the gas pedal. I only have a 5 mile drive to work and what little driving I do around town is close. That maybe the most of my problem. As to the injector cleaner dropping the mpg, I too would like some further explanation.
My other truck was a '93 Chevy with a 350 and about 192,000 miles and I still got 15 to 17 mpg. Just thought the newer Ford would be better , but never figured in the 4X4.

 

The short rides are most of it. The engine is not up to operating temp. for half the drive to work, using more fuel.