Just one other thing to throw out there. My Cats were damaged and I didnt find out till I installed the LT's that they were damaged. I didn't have a tune right away after the swap but noticed a dramatic increase in power and fuel economy. I drove the truck from Vancouver BC to Kelowna BC which is through the Rockies and got 16mpg going there and 19mpg after swapping them and coming back...

Maybe an exhaust shop do some kind of test???

Also take into consideration that I'm talking imperial gallons to the mile which are larger and therefore give me a higher mpg then when calculated with US gallons. so I would say 14-15 to a 17-18 US mpg.

 

i have been meaning to clean my air filter and change my front 02's.
i do try and always keep it under 2k rpm's tho

i also probably need to clean my throttle body...

 

Yea, I have a firefighter friend that suggested I would improve mileage if I replaced the cats...as they might be clogged due to being the factory originals. I want to do THAT as well---Magnaflo hi-flow cats....and I want to delete the pre-cats!

Is there some type of test to show flow??---DirtySCREW

 

00 f150 5.4 4x4 on highway tires stock size stock truck i was getting 19ish highway.. city was 15ish now with my 31's bfg A/t tires. stock truck. i get 14ish city and 16/17ish highway.. and i dont useally drive nice..

 

^^ GRRR

 

epa estimate is 16 highway for your truck, your getting 15mpg which is probably better than 75% of the other f150's out there that are like yours.

 

I got a best of 14.7mp(us gal) city the other day. 33" goodyears. 120k miles.

 

Oh, I'm also running a CAI+K&N.

 

I ordered Motorcraft o2s from Rock Auto yesterday...they are on the way. We'll see if that helps----DirtySCREW

 

I've got an ext cab 06 4.6L stock wheels k&n 77 series CAI and oil filter ands driving home from college 175miles it takes me 8 gallons + a half a gallon if a stop or 2 is made at cruise control 73-76mph. And ill put in a gumout or seafoam I think its called, the red and white can for fun abt once a month. And make sure you clean your air filter!

 

My 02 Screw FX4 5.4 gets roughly 15-16 mpg cruising around 55-60. My truck has 136k, only mods are dual exhaust, hacked factory air intake, and an Edge Evolution. I do, however, run premium fuel with the Edge. If I run long periods around 40-45, I get 16+. Interstate is a complete flop, I think last time I checked it was 13-14 at best. The best trick I have found for better gas mileage is to leave it in park. I'll use my 02 CBR 600 F4i for gas mileage.

 

^^^ i agree, my escort gets 41mpg lol. the truck stays at home until the weekends. i drive it when i wanna look like somebody lol

 

Hey DIRTYSCREW, have you tried a Tornado? I heard on here some people were getting huge gains!!

 

ha ha------------DirtySCREW

 

I have a Mazda3 with the 2.3L for my DD.

But that's quite surprising. I actually got better fuel economy after I installed my mid-travel kit and the 4.56s, but I think that may be because the truck turns about 200RPM more at freeway speeds, so although the engine is turning faster, there's less of a load on it so it uses less fuel.

Kinda like the difference between riding a bicycle uphill in 21st gear as opposed to 1st gear. 1st gear, your legs are going crazy fast, but it takes a lot less physical effort to pedal uphill than if you were in 21st gear.

I have a Camburg 6.5, 35" BFG A/Ts, 4.56 gears, and an Edge Evo set to the tow only tune. I average about 18-19MPG on the freeway, and I also carry two full-size matching spare tires (which weigh around 200lbs total), 7 gallons of water (around 60lbs), a floor jack (40 lbs), a tool box (30lbs), and a box of miscellaneous recovery equipment (10lbs) wherever I go.

Before the lift and all the extra junk, I'd get around 15-16MPG on the freeway. My truck is 2WD though.