I have an 05, 100% stock, and recently calculated mpg by hand over about a 600 mile interval. Driving was mostly 65-75 mph with maybe 10-15% stop n go traffic. Bottom line was 16.4 mpg.

 

Wow that's bad mpg's! I just went on a 350 mile trip yesterday, and I was running 65-70 mph and got 21.4. Are you lifted with bigger tires? It's really strange how 1 6.0 can get great mpg's and another can stink? Seems that the 6.0's are not consitent as far as mpg's go!

 

here is where you can find the "lemon law" for mi:
http://www.michigan.gov/sos/0,1607,7...3885--,00.html

and for the record i got a v10 with almost 150k miles on it and not a single problem (knock on wood)

 

Congrats on the problem free trip

 

To Scottman70,
Is your Ex a 05 and have you performed any mods to it. In addition is you mileage hand calculated or by the fib-O- meter overhead display. I hope your calculations are right and would like to know how you are getting such great mileage.

Thank you for the input.

 

Don't know if this helps but on a long road trip going 60-65 ish I got 23.3 Hand Cal and my lie o meter said 23.9 not far off I think.

 

It's a 2004.Hand Figured. To be completely honest all I have done is a straight piped exhaust 3.5" and the zoodad mod, replaced the stock air filter with a new clean one, and I run the tires at 78psi. I get 16-17 in town and 19-21 on the highway. The more miles I get on this 6.0 the better it seems to do. 1 year ago I would barely get 19 on the highway...... It has recently improved, I think it's the warmer weather here in AZ. Or that it is broken in now? These 6.0's are all so different, my brother in law bought an 04 just like mine an can only manage 13 in town? You could line up 3 6.0's and they will all vary 2-5 mpgs??? I have no idea why?

I will say that my mpgs when I had 20k miles was worse than it is now at 53k miles. When new it would get 14-15 in town and 17-19 on the highway.

Doing the straight pipe mod really did get rid of the turbo lag big time and also did help with mpgs.....

 

To Toreador Diesel,
Thank you for the info. I should have remembered the re-learn new program time. I have been out of the business for 13 years. How much run time do the new processors require to learn? The bad rap my 05 is getting is because I still have my 02 diesel Excursion and it runs circles around the 05 with fuel economy and durability. Only a CPS, alternator and two batteries since new on the 7.3. What I'm trying to do is see if I can get my 05 up to speed or close to the 02. The 05 is smoother, quieter and a few more options plus it is a lot quicker although I DO NOT hot rod my truck. Any suggestion or comments about the vast array of fuel mileage difference posted for the 6.0s?

I can get almost 300 miles more to the tank on my 7.3. I only have a S&B and a Superchip microtuner on the 7.3. I know they are completely different engines but I would have thought that with all of the improvements on the 6.0 it would have got better mileage or close to the old 7.3. Is mine just a lemon s it seems to be? If I can not get the mileage up I see no reason to keep it especially with the RIDICULOUS ESCILATING cost of diesel fuel. The best fuel mileage I have ever recorded was 17mpg at 65mph 2000rpm. My 02 will get better than 21 at the at the same speed and rpms

Thank you again
Jeff

 

With the 6.0's if it's been reflashed a bunch the fuel mileage will be lower than those that have had no reflashes.

My wifes 00 X PSD has 186K miles and the only time it's left her stranded was when the CPS failed at 124K miles and when the alternator failed at 155K miles. The previous owner put a 100K mile full warranty on it and the OASIS report showed a head light **** being replaced. We bought with 104K miles and have been very happy with it.

It's towed some nice trailer loads. Went across the scales last Fall with the dump trailer with a 3/4 load and the scale read just over 25K lbs!!!

With diesel 80 cents to a dollar per gallon more than 87 octane gas sort of wished one of the three big vehicles was a gasser.

 

You guys are killing me with mpgs that you are getting. I wish I could get close to that.

I am going to remove my program DC the power to the processors and let it go back to a base line. Drive it for awhile and start over. I will leave the 4" exhaust and filter in and see what happens.

Has anyone experienced your converter clutch to unlock and then lock up after about two seconds when the cruise is set? In addition the truck will shift erratic with the cruise on at 70 mph. If use your foot no problem truck shifts like it should. I don't under stand why the cruise input would have on shifting.

I swear this truck is plagued and I'm geting very, very tired of chasing problems on this vehicle.

Thanks again to all

 

I wish you were down here in Texas, I'd really help you out. I've got two neighbors with 2004 6.0s and I'm their best friend. Once you detune, restart your truck and let it idle for 15 minutes, from there, regular driving will do the rest. (The same goes when you re-tune the truck as well) I don't know if you have to deal with the ULSD problem, but that affects your mileage sometimes more than anything. If you can find low-sulfur diesel (500 ppm) you'll get much better fuel economy as the ULSD (15 ppm) has less energy than LSD.

 

To Toreador,
I have been looking for LSD but I think all of the pumps have been forced to run ULSD in Michigan. I still have my 02 7.3l that lost a lilltle but 05 has never got decent mileage. From all that have posted there is something wrong with my 05. I am trying a few more things before I boot it thats the way I am. I like to exhaust all my resources.

I was afraid of the decrese in energy from the ULSD in addition I'm curious what the long term affect will be on pumps, injectors and fuel systems. Too bad we can not get back the old number 2 diesel. Engery per pound was significanty greater and not near the problems.

This cruise thing confuses me. Have no idea why it would effect the shifting. I under stand tip in, coast, or torque demand will cause a change in shifting but not at a constant speed. I have a kitchen that I have to finish so I will dig into this problem in the next week or so.

Is there any way that either I can contact you or you contact me? I realy like this truck but I am exhausted with all of the problems. As stated earlier I used to be master mechanic heavy truck and car but I left the field 13 years ago. I am up to speed on the 7.3 but unfortunately not the 6.0.

Thanks again for the valuable info and your time.