Question 6.0L Poor Milage

[Dogman]

My milage has never been satisfactory in my eyes. 10 to 12 all around and 16.9 strictly interstate averaging between 65 to 70 mph, all these averages with the truck basically empty and mot pulling much. 2006 f-350 4wd fx4 CC LB SRW w/ 3.73 limited slip, running synthetic oil with zoodad mod. Everything else stock. Tires are stock Continentals running about 60 psi. Starting to try some things. Have a Fitch on now for about 30 days, haven't seen any noticeable improvement. Looking into MBRP Turbo back. Thinking about changing all the fluids in the drive train to a synthetic. Have been looking into a sct but concerned about warranty issues. Starting to look at replacing tires, getting worn, looking for rolling resistance ratings on tires (looking at Toyo and michelin). I-Henry, I also can't understand why some of the guys are getting much better milage. I have about 33,000 miles on my truck at this time and it's never gotten any better since I bought the truck new in July of 06. I'm with I-Henry, what gives?

What size tires are on your truck?

 

[Fandini]

What size tires are on your truck?

Tires are stock, the ones that came on the truck..........let me look..........275/70 R18. I think that works out to be about 33" in diameter and about 11" wide.

 

[Dogman]

My 04 has 265/75/16 and works out to 31" tires I think. Are you running the numbers by hand?

 

[Fandini]

Yes I do all my calc. by hand (Don't have a onboard computer on mine Anyway) Fill it until the fuel is at the top of the neck and won't go down anymore when I'm gonna do a milage calculation. I keep track of everything, since I bought it, price per gallon, where I bought the fuel, if I put an additive in with the fill up, engine hours and odometer reading at each fuel stop, even note maintenance and what brands of fluids I use in fuel log to see if anything changes. Nothing much has made any difference.

 

[f100cleveland]

I Just finished a 250gal. comparison between different tuners plus running with out cat or muffler. I tryed EGR deleted tunes plus economy, towing, and performance tunes from edge and SCT including custum tunes fron two tuners. I averaged 10.7mpg hand figured with speedometer corrected with GPS. Best was 13.47 and worst was 7.86mpg. About half was towing 6600lb camper or 14k 3axle trailer. All I can say is the 01 did as good a job towing and got alot better mileage but the 06 rides better. Don't know what I can try to improve mileage tho. Stock was as good as the tunes for MPG but the tunes were alot more fun and towed better.

 

[Dogman]

I found this looking for something about fuels and mileage.

YouTube - Motorcraft Cetane Boost Video

 

[catch03]

the truck i'm looking at is a 03 6.0 auto with the 4.10 gear i hope it gets half what my 06 dodge gets i get 22.2 on the highway at 65mph it is a 5.9 cummins auto 3.73 4x4 dually

 

[catch03]

i like the cummins but hate the trans and the rest of the truck wish i had the cash to get a 08 f450

 

[ponyexpress94]

I found this looking for something about fuels and mileage.

YouTube - Motorcraft Cetane Boost Video

Dogman,

I can't seem to access the video, could you summarize what the video says about the Motorcraft Cetane Boost Additive. Thanks.

 

[Dogman]

Dogman,

I can't seem to access the video, could you summarize what the video says about the Motorcraft Cetane Boost Additive. Thanks.

The feds. don't requirer gas station to put the amount of cetane in diesel on the pumps, some stations tested show less then 40 cetane are trucks should have 40 or higher cetane. Having low cetane is one of the causes of EGR getting durty and bad fuel mileage.