It looks like this towing 8000lbs

 

that wasn't slow for a 5.4 pulling that type of weight

 

I'm not upset with it

 

First off ....
I've been self employed as a performance engine builder for @ 19 years....engine dyno equipped shop.....in 2004 I went back into the engineering field as a mechanical designer (defense contractor) as well as monitored several projects that have gone thru very strict military testing at a well known east coast testing center... so basically I'm saying I pay very close attention to detail and before and after results....


that said....
I run a 04 f-250 4wd s/d c-c short bed 5.4 auto trans (stock 3:73 gears)....


elevation ranges from sea level to 2,000 ft...


very hilly terrain (NEPA)


truck specs are ....


5" lift 35" bfg km's (narrow rims, inside wheel well) cab high leer cap.....
present mileage 36,500.....


performance mods are....
1) cold air intake (small perf gain)
2) synthetic fluids through out truck (little or no gain in performance or mileage. (still recommend for towing)
3) y-pipe conversion.... (very noticeable perf gain above 3,000 rpm) highly recommended....pulls a lot harder from 3 to 5,000 rpm also off idle....better mileage
4) perf muffler with 2 tail pipes (good perf gain from idle thru 5,000)
5) trans go shift kit....(much better shift and shift points small perf gain possible gain in mileage).. diff did not lose perf or mileage
6) gear change....I did a lot of work on figuring gear....4:88 (major perf gain little or no loss in mileage....highly recommended
I run 68 to 73 mph in od turn = 2400/2500 rpm
drive (od off) 65 mph = 3200rpm
7) SCT tuner....took @ 4 trys..back and forth with SCT...(great to work with) I run either 87 perf tune or 93 perf tune... was the missing link to make the truck best it could be......


note.... tire air pressure...keep at max psi...


ALSO: VERY IMPORTANT.... I towed cross country...biggest variable I found...FUEL.....real eye opener....perf and mileage.....


so the breakdown goes....


mileage "before" any perf mods....
hi-way 12mpg (no tow)
hi-way 8.5 to 9mpg (towing 3,000)


mileage "after" perf mods....
hi-way 13.75mpg (no tow) "best mileage w/o cap 14.5mpg"
hi-way 9.3 to 10.3mpg (towing 3,000)


substaintially better running truck with perf mods....
(not that's its anything great, but it is a 330" engine)


please note....stock tires vs 35"....add 10% to miles traveled when figuring fuel mileage...exp 100 miles on odometer actual traveled miles 110/112...(also verify mph) verify with gps....


things to consider....
tru-dual exhaust..
5:13's.....
6 to 8 psi would help..


keep in mind I'm only reporting my findings....

 

Thread necromancer, engage!

Seems like an incredible amount of money and effort put into making a 12 year old 5.4L gasser marginally more acceptable.

 

Alright, Im gonna have to go through the hassle of doing timing chain tensioned guides etc. and thought that while I have it apart, why not throw on a set of cams. May play with the valve timing a bit to see if I can get some grunt out of it. I know this thread is old, and possibly buried, and no, I have not spent the time yet to dig through all that may be out there. I am new to the forum and hope I can get some feedback on wheather or not it is worth the money to make these upgrades? Or am I just dreaming?

 

Alright, Im gonna have to go through the hassle of doing timing chain tensioned guides etc. and thought that while I have it apart, why not throw on a set of cams. May play with the valve timing a bit to see if I can get some grunt out of it. I know this thread is old, and possibly buried, and no, I have not spent the time yet to dig through all that may be out there. I am new to the forum and hope I can get some feedback on wheather or not it is worth the money to make these upgrades? Or am I just dreaming? 2003 5.4. Already chipped with exhaust.