NEED MORE MPG!

[StrictlyDiesel]

My 05 6.0L gets 14mpg highway DRY running the BullyDog GT (on Tow), 35" mud country's, and a catback exhaust no muffler. Rear end is 3.73. I know...its a truck, but most 6.0L guys i talk to average 17-21 mpg (chip or no chip) as so they say. Any ideas on how i can bring my mpg up. Remove cat? Air intake?

[smokersteve]

Go to the general discussion and there is one on mpg

[HeavyAssault]

Sounds about right for the mods you have currently. You could try an SCT with some custom tuning.

[jetjock15]

we all want more MPG... i dont even know what i get cause i really dont check to often, i usually dont run a full tank of gas without towing so its hard to gauge..... if ya cant afford the mpg go back to stock tires for a bit that will help a lot, being lifted gets a lot more wind resistance, then taller tires get a lot more rolling resistance... it adds up.... pay to play...

[xjeeper]

I think that something is wrong with the truck, I just returned from a 1300 mile trip in my modded 04 cc 4x4 on 285/75 mudders towing a lifted poppup trailer, hauling 2 motorcycles plus 5 passengers and a full load of gear, and my worst tank was 14mpg @ 75mph in a crosswind. My previous 04 cc was lifted 4" on 35" xterrains loaded with luggage and running an ARE shell, gibson exhaust,Airaid intake, and a dr performance chip, saw a worst highway tank of 13 mpg @ 80 mph into a stiff headwind. both trucks have broken 20mpg highway(the unlifted truck does so regularly).

[LHMissions]

Originally Posted by xjeeper

I think that something is wrong with the truck, I just returned from a 1300 mile trip in my modded 04 cc 4x4 on 285/75 mudders towing a lifted poppup trailer, hauling 2 motorcycles plus 5 passengers and a full load of gear, and my worst tank was 14mpg @ 75mph in a crosswind. My previous 04 cc was lifted 4" on 35" xterrains loaded with luggage and running an ARE shell, gibson exhaust,Airaid intake, and a dr performance chip, saw a worst highway tank of 13 mpg @ 80 mph into a stiff headwind. both trucks have broken 20mpg highway(the unlifted truck does so regularly).

Did you hand calculate or go by the console mileage numbers?

Without tuning (my banks took a crap - not terribly heartbroken about it - SCT coming soon!!!), running 35's and spritited as I can be without a tune - and without the shell, my last tank was just over 10.4mpg. Combination highway/city.

With the Banks - my mileage was in the 14-17 combination range.

Truck in the signature on 33's (pic is with the 35's), and Banks on level 4 - I one time got 22 on the highway - empty and holding speed around 60mph.

[rkadc]

I'd have to agree that sounds about right, back when I was running the factory 20's on 35s, edge juice, and 4" duals got about 14.7 to 15.4mpg, hand calculated.

[StrictlyDiesel]

ya i hand calculated my fuel mileage. Even calculated the slight increase in travel i get due to the bigger tires. For me its like 36 km more per tank than my odometer records.

[obsidian]

Those tires are KILLING you.

Try a cetane booster for every tank.

You can also change the oil to another thinner 30wt oil. These trucks shear the 40wt down to 30wt but they don't shear the 30wt. Check my sig for more info.

[xjeeper]

I also hand calculated, and used centane boost on most fills, but not on the worst tanks, also winter blend diesel seems to cut mileage. Even so 14 mpg is auwfully poor, I suspect a loss of boost or compression, these trucks can seem to run fine with a blown head gasket or cracked valve seats. (I know from experience)