Horrible MPG?

[dstryr]

06 6.0 61,000 miles
SCT tuned with SRL from Matt @ Gearhead
6" fabtech lift on 35's
3:73's

Just got the oil changed to synthetic and did the fuel filters....Ever since I bought it 3 months ago I've only been getting about 300-320 miles to a tank and I have the 28 gallon tank. 11 mpg for a diesel? I figured atleast 15?

What is wrong with my truck? I was figuring maybe an injector is clogged? What should I run through it to clean them out?

[01clj]

Big tires and lift kit plus running more power my guess is you us the go pedal a little hard. I can make my 7.3L with 6 spd manual get 12 mpg or 20 mpg depending on how I drive. That lift and tires will hurt the mileage alot and if that is city driving that ain't to bad. oh and I have 3.73 gears also.

[RescueF250]

Talk to Matt about what you have maybe he can adjust your tuning for you.

[jason]

i have a bone stock 2005 short bed crew cab 4x4, w/ 3:73's also,i added an airaid air filter. my mileage dropped to 15 hwy, from +/- 19/20 thats as long as i keep it below 2k rpm, and my foot out of it. i'm running a half a btl of ford/motorcraft fuel additive from my local dealer, in every other tankful, i did some reading on powerstrokehelp.com , and took my cat.converter off , and drilled the guts out of it, and now my mileage is back around 19-20 hwy.

[dstryr]

For the past 2 tanks I've kept it under 2500 rpms the whole 2 tanks...no improvement on how i drive. Also already have the cat and muffler delete.

Same miles per tank as when before I had the SCt....AND I adjusted for the bigger tires in the tune and still get horrible mileage.

[2005F250]

My 05 had 35's and stock gears and never saw above 12 mpg. I'de barley get 300 miles to a tank and I was freeway driving.

[RescueF250]

Thats odd, when I had mine on 37's and 3.73's I was getting close 18pmg towing a car behind me.

[yosh30]

I have 6" lift with 37's and highway driving I get right around 14.5-14.9 mpgs, city driving probably right around 11-12. I want to get 4.30 hoping vit would help my mpg's but spending 2000 or more is hard for me to throw out when the mpg might not be that big of a increase

oh yeah and those mpg's are with fppf fuel treatment, I just used my last bottle today.. I'm going on a 700 mile road trip in a couple weeks and will be using the revx fuel treatment, well see of that helps

[tyhackman15]

Airfilter? Fuel Filter? Make sure all your cylinders are firing, could have a leaky injector, etc...

Other than that I'm stumped

[helilog56]

Are you calculating the "old fashioned" mathematical way....or going by the onboard computer?? If the computer has not been recalibrated for wheel/tire size....the speedo error adds up pretty quick when trying to calculate mileage!

Hows the transmission been acting?