2005 Dodge 3500 Cummins Fuel Milage

[om21braz]

LD1,
I can't compare mileage figures with you as the CTD I had was a 2500 w/ 4.10 rear end. I can tell you that keeping the tach @2000rpm or preferably less is a big help for fuel mileage. Seems anything above that, the mpg gets progressively worse the faster you go. That said, the computer was always optimistic - usually 1-2mpg higher than actual.

 

[ModMech]

Well, this is kinda an update to this thread http://www.tractorbynet.com/forums/trailers-transportation/213745-finally-got-me-real-truck.html But I figured I'd start a new one since that one is old.

I gotta say, The milage is a little disappointing, but livable, but what is really disappointing is how far off the computer is Every other vehichle I have owned, including other dodges (not diesels though) has been spot on. My last 2003 chevy even had told how many gallons was used, and that was right on within 0.1 gallons for a full fillup.

Anyway, we took a road trip today to newport aquarium. I filled up before we left. I still had ~1/2 tank and 268 miles on the odometer. That 268 miles was mostly working the truck. Hauling loads of firewood as can be seen on my other threads, towing the kubota to a buddys and back to do some work, and scrapping a couple of cars. But the cars were only ~3000 lbs and the kubota weighed ~ 4500 plus my 2700lb trailer. So not really a heavy load for the truck, but no highway either.

That 268 miles took 23.7 gallon of fuel for a calculated figure of 11.3MPG, which I thoug was low. I was expecting ~ 14-15 given the loads and driving I did, and the computer said 15.6, so it was off by a good bit.

Anyway, we filled up right before getting on the freeway, and again right as we got home. Cruise was set @ 71 on the way down and 75 on the way home. Mostly flat ohio freeway right down I71 from 140 exit to just across the river into kentuckey. 284.6 Mile round trip. 15.89 gallons to top off.

Calculated figure of 17.9MPG. I can accept that for highway, but the computer showed 20.4:confused2:

So how many of you fellow Dodge CTD owners have actually hand figured, and compared to the computer???

Sounds like the computer is not correctly programmed for the tire size you are running or maybe the gearing has been changed?

That said, they call the on-board MPG stuff "lie-o-meters" for a GOOD reason.........

 

[techwrtr2]

MPG indicator in my car certainly is optimistic. Regularly tells me I'm pulling an average of 30 mpg.... and I haven't gotten that through calculation regularly for a long time. Only once this summer and that was a jaunt not to exceed 55mph.

If you want to keep an accurate record of fuel mileage, I found a nice Android app on Amazon that is great for keeping track of mileage as well as other basic auto maintenance. Logs records over multiple cars and even reminds you when something like an oil change or tire rotation is due.

 

[LanceH]

I've got an '05 2500 cummins 6 speed manual that just turned over to 200,000 miles. Since I bought it in early '08 with 81k on it, i've noticed the 'lie-o-meter' being optimistic. On all 55mph speed limit roads, i run about 60 or 64mph and the overhead says 26 or 28 usually, sometimes as high as 30mpg if i'm not running over 2000 rpm's. I dont use the cruise control and i will say that when i put a 5" straight pipe on it from the turbo back, my mpgs went up to 20/21 hand calculated. Again, that is not running superfast and usually not over 2000 rpms unless i'm smoking out a durajunk or riceburner.

 

[gengine]

My '05 and my '03 both are pretty much spot on with the "lie-o-meter." both are the 5.9 cummins cc 4x4 long box with the 6 speed, both 3.73 gears. Both have the bullydog triple. They, either hauling or "town" driving are usually within .1 or .2 mpg of the computer. We make a habit of resetting everything when we fuel up. Even the overhead. I'll tell you what, my 7.3 cannot compete with the fuel milage ( around 19@best), although when on the highway, both cummins turbos are spent while the 7.3 powerstroke still has some for passing. I will still take the cummins any day over the power stroke.

 

[JimRB]

My Lie O Meter is off by a few mpg. The truck is new to me with 138,000 miles. Over 3,000 miles I have gotten 18-20 mpg hand calculated with the tank filled to the rim. That topping off the tank takes a lot longer than it does for my diesel Jetta. 2004 2500 long bed with an automatic, 3.73 2wd. My goal is to getting the torque converter to lock up and generally I don't need to go much faster than the 50 it engages at. 60 is usually fast enough. I did move my little JD 870 and I got a light load of hay using the equipment trailer. It is easier to drive than my old toyota 1 ton.

Paved roads, semi rural driving usually.

 

[BigBoyinMS]

I have a 2004.5 SRW w/ auto tranny. I keep it on the 70hp program from my Smarty Jr and I also used the Smarty Jr to get the speedo spot on with GPS. I've hand figured every tankful since I bought the truck. When I was driving it back and forth to work every day (2.8 miles in town with 11 stop signs or redlights) I averaged 12.5 mpg. On the highway I would average about 19.5 mpg. I would average 15.5 mpg when my trip to work was 13 miles with 2.5 of that in town and 10.5 on the highway.
Here's a twist to that. About a year and a half ago I changed from 15w40 Rotella to the 5w40 Synthetic Rotella. I figured for the slight difference in price I would much rather have a synthetic. What I didn't expect, and didn't believe at first, was a little better than 10% jump in my fuel mileage. On the second tankful I had to make a 1000 mile (unloaded) round trip to the Houston area. I had the cruise set at 75 mph and when I got there I filled up and drove back within the hour. Mileage going was 20.8 and the return trip was 21.4. In town mileage went from 12.5 to 14.5. No, I didn't change my driving habits. I still get on it pretty good and don't baby it. I just finished figuring the mileage from the last tankful. I drove it as usual for half a tank and my wife took a 300 mile round trip on the highway and I'm sure she babied it and probably had the cruise at just under 70 mph. That tankful averaged 19.8.
I'll be sticking with the Rotella synthetic.

 

[slowzuki]

I don't feel so bad about my gas F-350 now. It seems to get 12-14 mpg no matter what. Towing trailers, driving 50 mph or 75 mph, in the city etc. I do have to return to the 5w20 oil that is recommended I suppose and inflate the tires harder.

I spent 2 weeks commuting driving under the speed limit and planning my route, took all the extra junk out the the bed etc, no passing, coast to a stop etc, got 1 mpg gain for my efforts.