I don't have any performance details done to my truck, completely stock, I just went for looks, probably the hills that kill my gas mileage though, I can literally see my gas gauge drop when I floor it and hit 4000+ rpms...

 

have a 4.6 and drive like grandma.

 

Ya know what happens when ya hit full throttle and high RPM?
At about 7/8 throttle the program shifts to 'RICH' fuel tables, uncontrolled by the OX sensors.
The TPS tells the computer you intended this action, plus the RPM rapid climb that adds even more fuel courtesy of the TPS 'rate' of movement, and mass air meter airflow rate.
They all have input to the computer to mesure, fuel and time the ignition properly as well as shift the transmision at software max RPM points.
Ya play ya pay.
Just thought it was a good time to offer some insight.
Just like sucking soda through a straw. Suck hard enough and the level goes down fast even though the straw is small..
Good luck.

 

Wow after reading those two e-fan write-ups you found that has definately become a must do for me! Only downside is once the truck is quieter that knocking sound I have coming from the driver wheelwell will be more pronounced...

 

For what its worth, I've had Ford trucks for 40+ years. EVERY engine, gear package, towing package, etc.. I Always get/got 15-17 mpg. (avg.) Downwind, downhill, no load, maybe 18.5.

Towing a decent trailer of some sort, the mileage drops to around 9-10, on every truck. Always, and on every truck.

Now we have trucks with smaller engines ( displacement), but nothing changed except maintenance. Seems more frequent now, and definitely more expensive.

Trucks will be the last to see gains in mpg., because of fleet average.

Dave

 

I just noticed something this weekend that may or may not have something to do with my mpg. It finally got hot enough that I wanted to use A/C instead of just blowing cold air. Up till now, I had always been impressed with how cold of air this truck would blow. When i switched on A/C, the temp of air didn't seem to change. So, I am wondering if perhaps my A/C is stuck on?

I will search and possibly start a new thread for this seperate issue.