fuel economy

[BWalczak]

Sorry if this is in the wrong forum. I took my first trip in my '03 2500 4X4, quad, long bed, 6 speed manual towing a 7000# car trailer. 9MPG or slightly over. Flat, great weather, from Maryland to Miami and back. 300 miles on 35 gallons leaving some reserve. I expected better range since I easily get 500 miles without the tow. Otherwise great truck (my first big truck). Only 7000 miles on the truck which may contribute to the poor economy towing.

 

[CThompson]

I just returned from a 3K mile trip around Texas towing a 10K travel trailer 75 % of the time with a 03 2500 6 speed. Had only 3. 5K miles on truck when I left so was interested in mileage and checked it closely. Got from 12 to 14 depending on wind. It is about the same as I was getting on my 96 2500 5 speed before it was broke in, around 30K.

 

[Fred Swanson]

How fast did you drive?

 

[BWalczak]

I was averaging 75 on the way south and 70 on the way north.



My truck has the 4:10 rear. That may be the reason.

 

[Prairie Dog]

I've been getting 18 MPG calculated (20 on the overhead, )

going back and forth to work, which is mostly freeway. I'm going on a flat 3 hour, 65 MPH drive today on the highway - S/B interesting to check my mileage!

 

[Scooby]

CThompson,



Please describe your truck (incl. what gear ratio you have)



Thanks!

 

[CThompson]

Quad cab SLT. LWB with cab high Leer shell, ground effect running boards. 3:73 diff. Everything else is as delivered.

 

[Parshal]

Best Tank Ever

I just got my best mileage out of my last two tanks. I have a 5 speed, 3. 73 gears, short bed, quad cab and standard output engine. I got 22. 2 mpg (mostly city driving) and 20. 1 on the last tank (75 - 80 mph on the interstate only). Prior to this I'd been averaging 17 - 18 mpg. The only thing I changed was to add 5 psi to the front tires (now 50 psi) and 2 psi to the rear (now 46 psi).



All mileage is calculated by hand after every fillup. I have almost 17k miles on the truck now and most of that has been 400 mile trips averaging 70 mph. I get better mileage city driving. I get about 12 - 13 mpg towing a 3600 lbs. camper.



Even though the worst mileage this has ever gotten is better than the best on my Tundra I'm still a bit disappointed. I was hoping to be closer to 20 mpg all the time.

 

[JohndeereG]

Originally posted by BWalczak

I took my first trip in my '03 2500 4X4, quad, long bed, 6 speed manual towing a 7000# car trailer. 9MPG or slightly over. Flat, great weather, from Maryland to Miami and back. 300 miles on 35 gallons leaving some reserve.

I wouldn't believe it if I didn't actually do the math. I am getting 19. 2-20. 1 with my 03 truck display is within . 2mpg. This is particularly interesting because we drop mpg with winterized fuel here in W. PA. I have a 4-door, HO, 6spd, short box, stock truck. Now my brother has an 03, SO, 5spd, long box and is bouncing between 13-15. Same fuel--same speeds 70mph. I shift around 2K rpm.



With that said, if I drop my mpg. . ITS YOUR FAULT:{

 

[JohndeereG]

Re: Best Tank Ever

Originally posted by Parshal



Even though the worst mileage this has ever gotten is better than the best on my Tundra I'm still a bit disappointed. I was hoping to be closer to 20 mpg all the time.

Shame on you for using vulgar language on such a fine website as the TDR. Tundra... smunda



Translated to... I want to be a CTD someday. :-laf

 

[4xquadrod]

My last tank figured out to be 14. 5 mpg

4x4, 4. 10s auto and 35" tires. When I first purchased I was getting btween 10 and 12mpg. I currently have 6200 miles on it.

 

[Swayse]

First tank of mixed driving was 16. 3 mpg, overhead said 16. 2 with the stock tires. Made a short trip to the big city today, filled up before I left, some big city driving and filled up again before I got home. I racked up 155 miles, add 9% for the 315/70/17 = 168. 95 divide by 4. 6 gallons 36. 72 mpg, overhead said 16. 5 mpg. I filled it to the top so that's not the problem, I guess they had really big gallons. But still, if you go by the overhead computer and add 9 % for the tires, 17. 985 mpg. Not bad, I've got a little over 1150 miles on it now. 3. 73 gears. Love this truck.

 

[Swayse]

I drive 70 to 71 mph by GPS, about 65 on the speedo.

 

[dnitzel]

First tank 14. 8 and second 11. 8, all calculated. Over head read 16 to 18, and 14 on the second.

 

[scarlton]

I have 3. 73 Gears, 35" tires, HO 6spd, Edge EZ and I got 15. 8 on last tank, overhead said 18. 9

 

[Briman]

First tank = 17. 23 w/ winterized fuel (#2 with 20% #1 and additive) Calculated, not trip computer.

 

[VietDoc]

35 inch tires & Mileage

scarlton & 4xquadrod,

Have you had your ECM re-flashed for the larger tires??



On our '99 I had 285/75R16's about 33 inches and found the odometer was a good 10% off. For 150 miles I read the mile posts to make sure.



If you are calculating miles/gal based on the odometer miles you could be getting better miles/gallon than you think?? 10 to 20% better...

doc

 

[scarlton]

Vietdoc

I have not had it calibrated. I do not think it would be any more than 10% better. But you are right it really is a little better than calculated because of the taller tires.

 

[EnLjones]

I took mine down to northern Oregon this past weekend which included one mountain pass and one valley pass 6% grade in a couple of locations. 350 miles one way running at between 75-80mph figured the numbers by hand at 17. 3. Coming home same distance with head wind running same speed, numbers came in at 16. 8. I've got 1438 miles on her so far... and she's only two weeks old!

 

[4xquadrod]

I took my truck to a speedometer shop and they instructed me to add 7% to the miles to figure my mpg.



At 70 mph I am actually going 73 mph. They said my truck was at 93% accurate.



One thing I thought was strange was at slower speeds like 40 I was actually at 41. The faster the truck goes the less accurate the speedometer is.