I am not a happy camper.....

[klenger]

Barry:



There have been several reports of bad injectors with the 600's causing bad milage. Hopefully Dodge, Cummins, and the dealers will learn how to diagnose these problems and get them fixed.



I am getting about 2 MPG lower milage with my 04. 5 (17 MPG) vs my 01. 5 (19 MPG) driving empty, and maybe 1 MPG less when towing (9. 5 vs 10. 5). I attribute the lower milage to 3 things: New 2004 emissions requirements for the 600, no front axle disconnect on the 04. 5, and the truck is not broken in yet. I predict that after my truck breaks in, my milage may go up 1 MPG or so, but will never be as good as my 01. 5. My 01. 5 even had 4. 10 gears compared to the 3. 73's on the new one. Asside from the slightly lower milage on the new truck, I really like it, especially the quiet, the 4 doors, handling, etc.

 

[MikeKelley]

It now has become quite apparent , that the best thing DC can do to increase mileage on these trucks is to get rid of the overhead computer and thus force you to hand check it. The guys hand checking get MUCH better mileage. Mathematics don't lie.

MK

 

[randyn]

Barry,



There was a report of dyno results showing that the computer was de-fulling because of the air/exhaust mods that were done. The discussion then went in the direction of boost fooling. Apparently improving air/exhaust causes the boost to go up..... Do a search on VA. Wish I could remember more, but my bottom line understanding was that I was going to have to get some kind of box that has boost fooling even if I want better exhaust.



RandyN

 

[Turbo Tim 1]

Originally posted by Mikelley

It now has become quite apparent , that the best thing DC can do to increase mileage on these trucks is to get rid of the overhead computer and thus force you to hand check it. The guys hand checking get MUCH better mileage. Mathematics don't lie.

MK

He went 300 miles and had to fill up his 35 gallon tank, if he put in 30 gallons that's 10 miles to the gallon, pretty easy to figure. I hand figure every single tank of fuel I put through my truck and still don't get that good of MPG so there goes that theory. I can fill my truck, drive 100 miles and look at the gas gauge and tell you if it is 50/50 kero mix or straight diesel. I keep everything written down on a spread sheet, but I can fill up and calculate in my head what the MPG was, I'm sure Barry can too.

 

[favord]

My overhead has been nearly spot on when I compare to hand calculations so I'm not questioning the math.



I'm with Barry - it's not too hard to figure the mileage is just plain poor if you can't go 300 miles between fill ups and that's the situation I'm in pulling a trailer. I don't think I've ever drivenmy truck 300 miles straight empty except for when I bought the thing and drove it home from the dealer. My empty calculations are based on short trips - usually 12 - 13 mpg.



It's great to hear the posts of people getting great mileage with their 89 - 04. 5's. Other than illustrating it is possible to get good mileage it does little to help figure out the mileage problems we're having. I think I've read every thread on here regarding poor fuel mileage on the 04. 5 and I'd bet 90% of the responses are people telling how good the mileage is on their rigs... great but not helpful. Sorry for griping - just would like to troubleshoot this problem.

 

[klenger]

favord: I feel your pain and agree with your frustration. I do think it helps to hear about the higher milage 600's so that we can determine that low milage is not the norm for them.

 

[doldenburg]

I havesaid before, it seems to be a 04. 5 problem. most everyone responding has older trucks. we are not asking you all why,we are reporting ****y mileage. most of us are not green,we know how to check mileage and our trucks. I'm on my 4th dodg- cummins and the 04 1/2 gets the worst mileage. also like Barry said it does seem not to have the advertized hp.

 

[Barry]

Randyn: Very interesting! I have opened up the exhaust and the intake with an AFE7. Something that really surprises me is I can easily just over 30PSI boost... ... ... . STOCK! It will hit 30. 2 or . 3 and then fall back to 28 or 29 and change... ... ... .....



Is there some sort of "Silver Bullet" flash that is available from DC?

 

[Barry]

Randyn: Very interesting! I have opened up the exhaust and the intake with an AFE7. Something that really surprises me is I can easily just over 30PSI boost... ... ... . STOCK! It will hit 30. 2 or . 3 and then fall back to 28 or 29 and change... ... ... .....



Is there some sort of "Silver Bullet" flash that is available from DC?

 

[Barry]

Randyn: Very interesting! I have opened up the exhaust and the intake with an AFE7. Something that really surprises me is I can easily just over 30PSI boost... ... ... . STOCK! It will hit 30. 2 or . 3 and then fall back to 28 or 29 and change... ... ... .....



Is there some sort of "Silver Bullet" flash that is available from DC?

 

[GWoody]

I really like my truck, good power except the fuel mileage, 4200 mi. now. Mathmatic calculations are usually close to the overhead. I hope someone starts building some type of lockout hub for the fron end, I think that would help the mileage some.

 

[DocDetonancour]

I have to wonder how many are taking the extra 10 minutes of Pump Pump Pump to fill these things. At least 3 gallons more till you can see the fuel at the cap.

 

[Turbo Tim 1]

I think the post that randyn was taking about said you need a box, can't remember for sure but I think the thread was started by Joe Donnelly maybe. I looked for it real quick but didn't find it.

 

[Flores]

Just took a trip to Vegas this weekend. Going between 75 mph to 90 I got 13. 7. I didnt hand calculate this time but when I do the overhead is ALWAYS more generous by at least . 5 to . 75 mpg.

 

[RTuvell]

Can We Blame It On the Tightening Emissions Standards for Diesels?

The low MPG explanation for the 600 that I've seen posted on this board and seems the most plausible to me is the third injection event required to keep the catalyst active and the air pollution emissions low. There just doesn't seem to be any other major changes from the 555 to the 600 that can explain the fall off in MPG other than ECU programming.



The 600 is the first to meet the new emissions limits that progressively get more stingent through 2007. IMHO the manufacturers have not completely sorted out the best ways to meet the emissions limits and it wouldn't surprise me to see these problems continue through the next few model years until things get sorted out. I hope I am wrong about that!

 

[Turbo Tim 1]

I found the thread that I was thinking about earlier, it was actually Ted Jannetty and an 03 truck but the situation might be similar on the 04. 5's hope this helps some.



Defueling

 

[Elite1]

I thought it was interesting that at a recent Dyno day in Calif. , the stock 03' 305/555's were dynoing higher than the stock 04. 5' 325/600. (260 vs. 245 HP) Granted the 600's arent as broken in, but Sounds to me like the 600 may have some issues...

 

[randyn]

GWoody, Barry,



Barry, Turbo Tim 1 found what I was reffering to! That tells me that could be hurting your mileage if it's hurting your power.

Gwoody & others, keep an eye out for "Serviceable Lock Out Hubs" in the 3rd gen. non engine/trans forum, it will be a while, but I think it will happen, not sure of cost yet, but the "Super Duty" kit compontents they are working on now may be useable on our axles too (according to them). This has to help mileage some. '



RandyN

 

[Barry]

OK boys and girls, I stopped and filled up last night to check my mileage by hand. I had the truck sloping away from the pump and I "packed" the tank.



It took 30. 535 gallons and I had gone 289. 2 miles for a true of 9. 47 mpg. The computer was reading 9. 2 when I reset it last night.

 

[CNichols]

Wow thats bad



Hope they get it figured out for you 600 guys.