Disappointed in the 05 600...Fuel Milage Once Again

[joeyou]

My truck is a 2500 longbed. Yeah, I too miss the mileage I got with my 99 & 95 Rams, but if I can consistently get above 18 mpg, then I guess I can live with it. I do like the rest of the truck, and the extra power is good too. By the way, on the second tank where I got 18. 1, I had about 800 pounds in the bed the whole tank and spent about 50 miles in a steep hilly area running the **** out of it to seat the rings in good.

 

[Pit Bull]

My truck is a 2500 longbed. Yeah, I too miss the mileage I got with my 99 & 95 Rams, but if I can consistently get above 18 mpg, then I guess I can live with it. I do like the rest of the truck, and the extra power is good too. By the way, on the second tank where I got 18. 1, I had about 800 pounds in the bed the whole tank and spent about 50 miles in a steep hilly area running the **** out of it to seat the rings in good.

I hear you, I want a new 3500 QC 4x4 "600", just because I love the Cummins, the looks of the new trucks and the dually. I now don't really tow or haul and could get by with a 1/2 ton or SUV, so that is why I was hoping the MPG would be around 20+ for the truck I wanted. It would be leverage to make me feel I was making a good decision. But with the fact being that with my driving mix of 50/50 and the fact that I would be buying the heaviest 3500 I would be getting around 14 mpg. Not a selling point

 

[joeyou]

The diesel option will more than pay for itself in residual resale value in about 2 years.

 

[BrittonTurner]

I have to believe that you guys who are getting 14 highway without towing are driving with a lead foot or are relying on the overhead console for your mileage numbers. The overheads have never been accurate! Also, I'm wondering if some of you reporting these numbers mistakenly have your overheads set for metric thus reading L/100kM... this will give you a reading of about 12. 5 L/100kM at 18+ mpg... . this may explain some of the numbers. I think we all should commit to only reporting hand calculated numbers on this site... also, reporting numbers after a 250-300 mile trip is not going to be accurate. The more miles you put on between fillups will lessen the error in where you top off.



It's all in how you drive.

Well I will have to respectfully disagree with you. When I started this thread I had only a couple hundred miles on the truck. So far I have almost 2000 miles on it and it has NEVER been higher than 13MPG. This is ALL hand calculated (although the overhead has been spot on every time). I don’t even leave it on the overhead console anymore because it is too depressing to look at. I only look at it when I am resetting it after a fill up. I have run each tank down to almost empty and filled it up the same every time so I figure I’m doing it right . I don’t drive with a lead foot. In fact I have babied the truck around just to see if I could get any better mileage out of it. I have NEVER driven the truck over 75 MPH but nothing seems to work. I drive a 50/50 average of hwy/city.



If I do use the overhead console going down the freeway (remember I said it was VERY accurate in my truck) it very rarely gets better than 15. 5 MPG. I just filled up the truck about 30 mins. ago and hand calculated it only got 12. 97 MPG. Overhead console showed 12. 9.



My 03 was exactly the same as this truck except it was a 305/555, 6 speed, and 4:10 gears. This one is a 325/600, auto, with 3:73. The 03 was averaging 18MPG 50/50 city/hwy. I know the auto will kill a little mileage but not that much. 60 MPH with the 05 it is running 1700 RPM’s. 60 with the 03 it was running 2100 RPM’s. Stands to reason that this one would get comparable mileage as the 03 but it doesn’t even come close.





If you have any suggestions…. I’m all ears.





Britt

 

[Winston Wolf]

Britt

Unless I missed it, I did not see any mention of you getting the TSB done.



If not, why not?

 

[BrittonTurner]

Unless I missed it, I did not see any mention of you getting the TSB done.



If not, why not?

the last that i heard it wasn't going to be available until the first of Nov. at least that is what the stealership told me.







britt

 

[Winston Wolf]

Britt

Maybe you are missing the numerous threads on this, including a poll of results here:



https://www.turbodieselregister.com/forums/showthread.php?t=113455



First thing I'd do is check you engine serial number against the range in the TSB to see if it even applies to your engine.



I've had my '05 about a week. My engine SN is greater than the range in the TSB. It looks like my first tank of fuel is going to come in at 15-16MPG mixed driving. My truck is similar config to yours except for 6 speed.



Since the TSB was for a range of SN's and mine is higher, I'd presume I'm running the same or greater code as the TSB. It'd be interesting to know for sure.



Anyone know if I can get a code revision out of the OBDII ?

 

[DPelletier]

Britt,

If it was me I would try the TSB and if that didn't work and it was my truck, I would consider injector replacement. For the most part the 600's are getting slightly less mileage than the 555's for the reasons I mentioned earlier, but there are some that are noticably worse, like yours. Unfortunately DC won't likely replace injectors because of poor mileage unless there is a driveability issue since the corporate response is " we don't make fuel economy claims with regards to diesel trucks". I think some of the wild claims of increased economy that some of the aftermarket injector companies are espousing are the result of replacing defective factory injectors on some trucks. I have no hard data to back up this theory, so take it for what its worth.



Dave

 

[klenger]

I think some of the wild claims of increased economy that some of the aftermarket injector companies are espousing are the result of replacing defective factory injectors on some trucks.

Especially since they claim that your milage may improve 3 MPG up to 20 MPG, but if you are already getting 20 MPG, expect no improvement.



I don't know if TSB 018-037-04 applies to any of the 05's. I suspect that the new software was developed for the 05's and then made available to the 04. 5's after it was tested on the 05's. I agree, if you are getting 13 MPG with an 05 driving conservatively, the truck is broken (most likely injectors).

 

[joeyou]

Well I will have to respectfully disagree with you. When I started this thread I had only a couple hundred miles on the truck. So far I have almost 2000 miles on it and it has NEVER been higher than 13MPG. This is ALL hand calculated (although the overhead has been spot on every time). I don’t even leave it on the overhead console anymore because it is too depressing to look at. I only look at it when I am resetting it after a fill up. I have run each tank down to almost empty and filled it up the same every time so I figure I’m doing it right . I don’t drive with a lead foot. In fact I have babied the truck around just to see if I could get any better mileage out of it. I have NEVER driven the truck over 75 MPH but nothing seems to work. I drive a 50/50 average of hwy/city.



If I do use the overhead console going down the freeway (remember I said it was VERY accurate in my truck) it very rarely gets better than 15. 5 MPG. I just filled up the truck about 30 mins. ago and hand calculated it only got 12. 97 MPG. Overhead console showed 12. 9.



My 03 was exactly the same as this truck except it was a 305/555, 6 speed, and 4:10 gears. This one is a 325/600, auto, with 3:73. The 03 was averaging 18MPG 50/50 city/hwy. I know the auto will kill a little mileage but not that much. 60 MPH with the 05 it is running 1700 RPM’s. 60 with the 03 it was running 2100 RPM’s. Stands to reason that this one would get comparable mileage as the 03 but it doesn’t even come close.





If you have any suggestions…. I’m all ears.





Britt

Britt,



Just out of curiousity, is the truck completely empty with these figures? Also, are you located in a high altitude/mountainous area that might affect mileage? With fuel economy, there are so many variables, but it does sound like you've got a problem.



Joe

 

[BrittonTurner]

Britt,



Just out of curiousity, is the truck completely empty with these figures? Also, are you located in a high altitude/mountainous area that might affect mileage? With fuel economy, there are so many variables, but it does sound like you've got a problem.



Joe

Almost completely empty. The camper shell is 550 lbs. The only thing is it was also on my 03 and the 03 got great mileage. I am going to make a appointment tomorrow for the TSB. Hope that helps. If it doesn't then I don't know.



Little Rock is 347Ft. above sea level so altitude shouldn't be a problem.





Britt

 

[jsimpson]

The camper shell should help fuel mileage, as long as it doesn't stick up higher than the cab.

 

[cwcox]

I've recently spent some time in an '04 2500 4x4 Quad Cab short bed, 600 and 6 speed, with a 3. 73 rear. I was way impressed with the power, and the fuel mileage averaged 21 on the highway. I didn't do enough around town to quote a useful number, but it didn't seem to be any less than 17. This truck has 10,000 miles on it, so maybe they loosen up just like the 12 valves. My 95 ran ok until 60,000 and then power and mileage shot way up. Also, when I hit 105,000, the driveability and power increased again. I imagine the new 600 would follow suit. PS: on the injectors, dealer friend has already had 3 juiced up trucks with burnt up cylinders due to leaking aftermarket injectors. Buyer beware! He didn't mention any brands, but this dealer is real cool- he had the owners take trucks home, swap in factory parts, and then he got repairs covered. He's risking his hiny for his customers.