7.3 fuel mileage sucks!

[catsnw]

I am posting for my dad so here it goes. My dad has an 02 f250 with an auto and 3.73 limited slip rear axle (its a 4x4). The engine is bone stock except of the drop in k&n (bad I know). It has a 4" lift with 265/75/20. We went camping puling an 4500lbs (empty) travel trailer. We went from south Louisiana to Kentucky. Fuel mileage average anywhere between 8-10mpg. This is going by distance traveled/amount of fuel put in. We were cruising at about 65 mph most of the way except for the hills where it went 55ish.

I drove the truck and I swear this thing is gutless going up semi steep hills. It would downshift and I would have my foot to the floor and the speed kept dropping. Is this kind of behavior normal for this truck???

BTW my dad wants some more power out of it(and mpg's) so he wants an AFE intake and a 5 inch turbo back exhaust split to duals. Anything else to look for?

Thanks! I tried searching but I suck at searching.

[fifty]

Call Power hungry performance (PHP) and get their chip...that will help the power, mileage and shifting.

[Jarrod B]

im gonna assume you have changed your fuel filters?

ya get a chip.

[renoduckman]

Fuel MPG is relative i guess. I have recently been fighting a drop in my normally excellent MPG. But just the combo of changing the fuel filter and haveing very dirty intercooler boots cleaned and reinstalled brought my MPG back up about 2-3 MPG. Now dont know if it was the filter or the boots but made a big difference. Joe

[ToMang07]

Yeah, check out all your clamps, the ones on the spider, (5), the up pipe to the turbo, the up popes that feed into the collector behind the turbo for soot, and the intercooler boots/clamps for leaks/cracks. Check the turbo wheel for play and see what the fins look like. Should look like this:



Definately sounds like a boost leak or other issue if you have 3.73's.

[Jarrod B]

if you had a small leak, you couldnt build much boost right? i can hit mid 20s with tunes.

[ToMang07]

Originally Posted by Jarrod B

if you had a small leak, you couldnt build much boost right? i can hit mid 20s with tunes.

Before my WW/Turbo Master, I could hit 30-31psi w/ the red line unplugged. I can peg 26-27 pretty easy now which is where my TM dumps the boost. Hell, i can squeeze ~15psi just getting on the throttle without shifting if I do it right!

[Jarrod B]

Originally Posted by ToMang07

Before my WW/Turbo Master, I could hit 30-31psi w/ the red line unplugged. I can peg 26-27 pretty easy now which is where my TM dumps the boost. Hell, i can squeeze ~15psi just getting on the throttle without shifting if I do it right!

I can get boost just fine but I haven't seen above 28 wot on extreme tune . Otherwise on moderate accel it's around 20 psi.

iPhone

[ToMang07]

Originally Posted by Jarrod B

I can get boost just fine but I haven't seen above 28 wot on extreme tune . Otherwise on moderate accel it's around 20 psi.

iPhone

Sounds good then!

[catsnw]

Also highway/city the truck gets about 13ish will no load. Something isn't right. Will check turbo, clamps, and boots.