10.8 mpg in my 6.0 liter.. What the heck??!!!?!?

[fabb0429]

i have an 03 CC lariat 4wd psd with 55k on it. its lifted 6in with 35" toyo's. only mod is a 4"tb exhaust with kitty and muffler(came like that when i bought it). i'm lucky if i can get 300 miles out of a tank of diesel. i don't drive it hard, i haven't towed anything with it yet, what is going on? i've heard of some people with bigger lifts than me getting 18mpg+!!!

how do i do this?? if i could get 15mpg i would be stoked!

regear axles?
sct tuner?
cut off kitty and muffler?
intake?

i'm still under ford esp extended warranty too.

driving down to AZ next month, towing a small trailer, would like to improve my situation before then.

any help is much appreciated!!

[s8v4o]

Are you always getting on it? I just recently got an 05 F250 4 door (weighed 7370lbs bare) and I've been averaging 14.5 mpg. That's mixed driving with plenty of spirited driving. I know it could get better than that if I drove it easier. Also I got the truck last week but this week I tried my SCT livewire (borrowed from my mustang) and it worked great. Picked up a bunch of power. It's much more fun to to drive!

On that note before doing an mods I would try to figure out why you are getting low mpg. How do your filters look, air and fuel? Have they every been changed?

[mike517]

I get 20mpg crusing at 70 and about 13mpg with 2 ATVs onboard while towing 23 foot trailer

[dhanna6powerstroke]

Originally Posted by fabb0429

i have an 03 CC lariat 4wd psd with 55k on it. its lifted 6in with 35" toyo's. only mod is a 4"tb exhaust with kitty and muffler(came like that when i bought it). i'm lucky if i can get 300 miles out of a tank of diesel. i don't drive it hard, i haven't towed anything with it yet, what is going on? i've heard of some people with bigger lifts than me getting 18mpg+!!!

how do i do this?? if i could get 15mpg i would be stoked!

regear axles?
sct tuner?
cut off kitty and muffler?
intake?

i'm still under ford esp extended warranty too.

driving down to AZ next month, towing a small trailer, would like to improve my situation before then.

any help is much appreciated!!

Welcome to the ORG. Your lift isn't helping your mileage any. I would cut off the CAT and Muffler, should help some and will definetely sound better. Get an SCT with custom tunes. Where are you from? Right now the winter blended fuel will cause mileage drops. I have went from 16-17 to 10-12 and it does it every year.

[hoosier golfer]

X2 on the filters, I'd go through it and change the oil & fuel filters.. That might help some. A 4" Turbo Back exhaust would defiantly help but I would check with the dealer first to make sure it's not going to void the warranty. Next I would pull the EGR Valve out and clean it. If none of that helps, have someone hook it up to a scanner & check the injectors 1 or 2 of them might be failing. Hope this helps!

[metstroke06]

I went from 18 mpg, to 13.5 mpg after 8" lift and 37" tires, and I run custom SCT tunes, I'm regeared, and that is driving 60-65mph. Either it's the winter fuel because I got it lifted this past Fall, or it's the tires/lift.

[dhanna6powerstroke]

Originally Posted by metstroke06

I went from 18 mpg, to 13.5 mpg after 8" lift and 37" tires, and I run custom SCT tunes, I'm regeared, and that is driving 60-65mph. Either it's the winter fuel because I got it lifted this past Fall, or it's the tires/lift.

Probably a combination of both.

[Deadeye_88]

i have been having the same problem. when i pull my trailer with firewood i usually avg 15 to 15.5 driving 65. now the past couple of trips i have been avg 12.5 to 13. someone told me that it might be the maf sensor. that i need to clean it. in town i get 13 to 14. its not great from everyone else. i dont how they are getting good mileage.

[soutthpaw]

Any type of oiled air filter such as K&N Filter will totally wreck a map filter reading because the oil and any dirt will stick to the sensor and screw up the reading...
Also check for exhaust leaks including exhaust manifold and also check your backpressure and boost readings... those will help indentify if you have a leak or excessive blockage such as a fouled up cat... post your results values here and we will be happy to give more input...
also check for fuel leaks... not sure about 6.0 but can be common on 7.3s look in the valley on top if the engine. if its wet something is leaking
are you getting any black smoke when you accelerate???
Not sure about 6.0L mileage either but I am getting 14.5 around town with my 7.3 Excursion (Ford Excursion) | Fuelly
and it is running 35" W/4" lift

[jdillon71]

Keep up on filter mainanance and just wait for warmer weather so we dont have to run winter blend. I lost 3 mpg this winter, and I have a 10" lift on 37's with 4.56 gears. I usually get 15-16 and 18-19 Highway in the summer.