Anyone want to chime in?

[XJSuperman]

Don't trust the overhead either... . not a reliable way to get mileage. Your banks sixgun has most likely interfered with that as I know folks who tow 15,000 lbs and get better than 9 MPG. My overhead is nowhere near accurate with the EZ in the truck.

 

[DocDetonancour]

My 305 pulled 19 mpg from day one. Most I've talked to say that 315's will kill the mpg? They do look good doing it, IMO. Doc

 

[jebia]

"... wonder if they didn't have them programmed to do poorly until after a certain number of miles. "

Of course this makes you wonder why they would do such a thing. It seems that they would want everyone to get the best mileage possible to increase sales. It would be great if someone in the know from Cummins would pipe in.

 

[KFette]

Doc,



The day I drove my truck off the lot, it had 10. 7 miles on it. The dealer provided the customary tank of gas and I reset the OBC.



The first tank of fuel read 11. 5. Being a new diesel owner, I didn't put much weight into it. I figured it needed to have a couple of tanks through it before I could get an accurate reading. You are one of the many that have said they got between 17-19mpg right off the lot, so that is what makes me wonder if I had/have a problem.



At 700 miles I put the bigger tires on, and the mileage did "relatively" suffer. Everyones first response is that I put bigger tires and a leveling kit on my truck and that is essentially why I get bad fuel mileage. If I were getting 17-19mpg and the bigger tires dropped me to 15mpg, no one would've ever seen this thread.



I just cannot believe my fuel mileage is "normal", after reading other posts...



Take care, KFette

 

[Mike Ellis]

If you get a chance, it might be interesting to take an infrared thermometer along on a drive and check the temp of your transmission (assuming you don't already have a gauge), differential, and wheel hubs. If you have something dragging or transmission is slipping the energy is converted to heat and the IR thermometer lets you quickly see if there are any such problem spots.



Other than that, can't think of much else that could be spanking your mileage except for boost or computer problems...

 

[Firemedic 76]

13,000 miles,9mpg in the city and 13-14 on the highway. Driving around town,nothing aggresive (normal). Hwy, on the average 70-75 mph with cruise control. Fuel filter has been changed as has the oil 3 times. Truck is stock with exception of a AFE drop in. Do have vibration @ 68 up.

 

[KFette]

Wow!! I'm not alone...



I didn't see a sig, so I don't know how we compare...



Sucks!!



KFette

13,000 miles,9mpg in the city and 13-14 on the highway. Driving around town,nothing aggresive (normal). Hwy, on the average 70-75 mph with cruise control. Fuel filter has been changed as has the oil 3 times. Truck is stock with exception of a AFE drop in. Do have vibration @ 68 up.

 

[KFette]

Thanks Mike,



Since we are in the same area, can you recommend a good diesel shop, or a dealership that doesn't lokk at you like you have 10 eyes!!



KFette

If you get a chance, it might be interesting to take an infrared thermometer along on a drive and check the temp of your transmission (assuming you don't already have a gauge), differential, and wheel hubs. If you have something dragging or transmission is slipping the energy is converted to heat and the IR thermometer lets you quickly see if there are any such problem spots.



Other than that, can't think of much else that could be spanking your mileage except for boost or computer problems...

 

[Rhinohd]

Ok I have an 04. 5 4x4 quad with 5000 miles on it and I get 15mpg in the city. On the highway I do about 17. 5 Hand Calc... One tank while pulling a trailer with 2 quads (utilities) totaling about 1700lbs (including the trailer) I hit 18. 6 mpg. I always avarage 70 mph on the highway. My truck is bone stock with a 3. 73 and auto transmission.

 

[KFette]

If I were getting those numbers... I'd be satisfied!!



KFette

Ok I have an 04. 5 4x4 quad with 5000 miles on it and I get 15mpg in the city. On the highway I do about 17. 5 Hand Calc... One tank while pulling a trailer with 2 quads (utilities) totaling about 1700lbs (including the trailer) I hit 18. 6 mpg. I always avarage 70 mph on the highway. My truck is bone stock with a 3. 73 and auto transmission.

 

[Vaughn MacKenzie]

KFette, do you have gauges? If so what boost are you running at a steady 70mph? Take some notes of this anytime it's calm weather and you're running on level ground and this can be an indicator of how much parasitic drag your truck has.



Dually automatics are the worst for mileage, although I have seen older 24-valve dually automatics turn 18-19 on the highway.



Vaughn

 

[Mike Ellis]

KFette,



I have not had much work done on my truck, experience with the Dodge dealerships in Cleburne and Ft. Worth has been generally poor and I have not had any work done by a diesel performance shop yet.



I can recommend a great mechanic who loves working on our CTD trucks, fellow TDR member Andy Redmond. He did the KDP fix on my truck a year or two ago when I was still gimping around after surgery. He is knowledgeable, friendly, a good mechanic, and very meticulous with his work. He lives in DFW area too.



I also noticed in the current issue of TDR that they listed in the very back some of the new Chrysler "Super Happy Golden Plus 5-Star" dealers, there were a couple in DFW area so maybe one of them would be worth visiting. My experience with the 5-Star routine is that they are no different than any other dealer, just a different sign. YMMV



Good luck bud

 

[JStraw]

I got 14 mpg right off the floor. First tank improved to around 15. At 800 miles I started hauling pallets of brick and top soil (3200-4500lbs). My mileage is now 16. 5 city 18. 9 highway. All highway speed is at 2000 rpms. I'm not sure, but I believe that by hauling heavy during break-in may have settled the engine in better. I'm at 2700 miles now and hope it can get better but sure am happy the way it is now.

 

[BIG BOB]

Dually automatics are the worst for mileage,



Vaughn

Boy Vaughn, you hit the nail right on the head! My average mpg since new is 13. 19 mpg! :--) :--) :--) :{ :{ :{ :{ I now have 27K on the engine and there is probably about 4K of towing in that average!



And I have the 555!

 

[GSpeed]

mileage

Geez guys I get 18-24 mpg (US) with my truck all the time (hand cal'ced)

I've got about 500 lbs. in the box all the time. (48 re)





I towed my brother's water tank the other day 950 gallons and a 2500lb. trailer and I got +/- 15mpg. (overhead)



Just like everybody says Mileage differs how you drive and even how you calc.

(Full Tank differences)