Dodge Cummins Diesel Forum banner

21 - 28 of 28 Posts

Registered
Joined
20 Posts
My 04, 3500 dually nv5600, is getting 19.5 mpg with no trailer on. (55-60mph). It weighs 8500# empty. Now up the speed to 70- 75, it'll drop some. But I come from the gasser gm truck world, with a truck weighing same amount, I was getting 7-10mpg. Also my 2nd gen 360 Dodge truck only got 8-9mpg.

So I'm happy as can be with this 5.9 Cummins truck at the moment. (This #9000 dually gets same mpg as my wife's Lexus rx300馃槈)
 

Registered
Joined
4 Posts
My old 90 12v gets 22 mpg normally. On highway about 23 if I keep it at 65. Towing goes down to 16 or less.
 

Registered
Joined
3,116 Posts
Just wondering why the new trucks with more power and more emissions seem to be more fuel efficient than the good ole 5.9?

I have a 2006 with slightly over sized tires (about 32" BFG AT KO's), drive the speed limt and the best I have ever gotten is about 18/19mpg on the highway.

THanks.
I want to see the new trucks that are actually getting better mileage than an apples to apples good ole CR 5.9. They are a fallacy, just like the guys who get 25mpg in their CR 5.9s, it's all relative. Throw the same bull chitters on mpg with new trucks with the group of bull chitters with older trucks and it all balances out.

Yes the old 12Vs and early 24Vs were more miserly, you could also outrun them with a model A ford too. CR engines a bit less mpg. 2008 emissions through 2010/2013, big hit in mpg. DEF trucks, mpg back to similar to CR 5.9s. That's what i see has happened.
The newer more powerful engines actually aren't quite as good on fuel, but other refinements (def, programming, more trans gears and higher rear gear ratios, primarily, secondary things like front CAD) have allowed the new trucks back into 5.9 CR mileage territory.
 
  • Like
Reactions: utahtrapper

Registered
Joined
3,116 Posts
As of right now, I can do over 800 plus miles per tank at 55mph easy. Keys to this,
Tire pressure I. E. Max the fronts, at least 65min. Rear.
Weight, with my 2wd, qc sb, with weight removed, I'm at 5950lbs. with a 1/4 tank of fuel.
Speed, anything over 60mph is killing you.
From a stop, never go over 6/8 pounds of boost, ever.
Tuning, fo sho, it truly does help tons, I just have a old smarty jr set on kill( max on all settings except torque management). Just abideing by those will help your mileage YUGE. From there, its the devil in the details like Steve has done exceptionally well.
True story, but I won't live long enough to drive freeways at 55-60mph! For fcks sakes, I'd have another birthday before I got to work in the morning driving like that!
And, I'd get flipped off and run off the road if I was trying to perfect my 10 second 0-30 time away from every stoplight and my how low of rpms can I possibly run in OD without lugging the engine strategy.
 

Registered
Joined
90 Posts
My 04.5 QCSB NV5600 on 37s, 6 inch lift and 4.56 gears managed just over 18 MPG hand calc'd. RPMS were between 2100-2250 speed was around 70ish MPH and cruise control was on.
 

Registered
Joined
159 Posts
I just got to witness a good mpg test of my truck compared to a 鈥17 F350 short box. A group of us has made a trek from western Washington to southeast Wyoming a few times to hunt. I have always taken my truck and towed my 27鈥 Enclosed trailer filled with quads, wall tent, freezers, and all the rest of our gear. I have consistently achieved 10.5-11 mpg, hand calculated on every trip. My truck has done this trip 5 times. Speeds are generally 75-85 mph. Empty, my road trips generate 18.5 mpg, but everyday mixed driving I am right at 14.5 mpg.
Well this year, we took my buddies new to him 鈥17 Ford and my trailer. His truck has 35k on it and is completely stock. Our mileage there and back was a pretty solid 9.5 mpg. Truck pulled the load easily through all the passes, though it was obvious mine was putting more power to the ground. I really thought the mileage would be a little higher for some reason, but it still was a pretty good comparison test. I did all the mpg checks, hand calculated, and was suprised to see his display was always right on with my calculations, if it was not exact, it was off by .1. My Dodge isn鈥檛 even close.
 

Registered
Joined
214 Posts
I just got to witness a good mpg test of my truck compared to a 鈥17 F350 short box. A group of us has made a trek from western Washington to southeast Wyoming a few times to hunt. I have always taken my truck and towed my 27鈥 Enclosed trailer filled with quads, wall tent, freezers, and all the rest of our gear. I have consistently achieved 10.5-11 mpg, hand calculated on every trip. My truck has done this trip 5 times. Speeds are generally 75-85 mph. Empty, my road trips generate 18.5 mpg, but everyday mixed driving I am right at 14.5 mpg.
Well this year, we took my buddies new to him 鈥17 Ford and my trailer. His truck has 35k on it and is completely stock. Our mileage there and back was a pretty solid 9.5 mpg. Truck pulled the load easily through all the passes, though it was obvious mine was putting more power to the ground. I really thought the mileage would be a little higher for some reason, but it still was a pretty good comparison test. I did all the mpg checks, hand calculated, and was suprised to see his display was always right on with my calculations, if it was not exact, it was off by .1. My Dodge isn鈥檛 even close.
Interesting. My work truck is a Ford and it consistently gets better mileage than my Ram and the Ford has more power (both stock) one of my biggest complaints with the Ram is the inaccurate EVIC when compared to how accurate the Ford has always been. Good to see I鈥檓 not the only one to notice that.
 
21 - 28 of 28 Posts
Top