Mileage difference 4.10 to 3.73 ?

[MFetzer]

I have a 2004 QC 3500 Dually 4x4, 4. 11 and the best mileage I can get is about 15 mpg on the highway cruise at about 68. How much mileage improvement will there be if I trade in for a 3. 73. I find that I am doing a lot of interstate driving and with fuel prices how they are I need to do what I can.

 

[Bertram65]

Doubt you will see any difference in mileage going from 4. 10s to 3. 73s. I have tried running at different RPMs for entire tanks of fuel and noticed little difference in mileage, anywhere from 1900rpms to 2500rpm, almost no difference. In my opinion all the talk about the big mileage drops from running above 2000rpm with the CR motors are a myth.

 

[fbadmaev]

I have a 97 3500 4x4 with 145,000 and I get around 17 mpg. When I had Michelin M/S tires I use to get around 19 mpg.

 

[macdaddy]

Thats about right

I have a 2004 QC 3500 Dually 4x4, 4. 11 and the best mileage I can get is about 15 mpg on the highway cruise at about 68. How much mileage improvement will there be if I trade in for a 3. 73. I find that I am doing a lot of interstate driving and with fuel prices how they are I need to do what I can.

MF

That's about right on the money. You got me beat by about 1 MPG. My 2nd genner same truck with an auto got 15. 5 both have 4;10's. Now matter how you slice the pie it beats the H*** out of the old GMC 2500 4X4 454 gasser :{



Mac

 

[Macker]

I would consider putting on an edge box. . just a 70 horse. . should increase your milage

quite a bit.....

 

[Diesel Dually]

I just picked up a '05 QC LB SRW 3. 73 NV5600 on Feb. 21st (Thanks Tomey Gun). I now have 1500 miles on it and noticed on the drive home that I would lose about 1. 5 mpg if I ran much above 2000rpm. My fuel economy ranged from 14. 8 on first tank and 17. 8 on last tank all hand calculated. My overhead is about . 5 to 1mpg optimistic.

So far I really like the truck but also very happy I kept my '96 dually.

 

[GCross]

Doubt you will see any difference in mileage going from 4. 10s to 3. 73s.

I agree. Even if there was a slight improvemrnt, I doubt you would ever re-coup the cost of the switch.



-George-

 

[DocDetonancour]

I have a 2004 QC 3500 Dually 4x4, 4. 11 and the best mileage I can get is about 15 mpg on the highway cruise at about 68. How much mileage improvement will there be if I trade in for a 3. 73. I find that I am doing a lot of interstate driving and with fuel prices how they are I need to do what I can.

I pull 23 mpg on Summer fuel, and 18 to 19 on Winter fuel in Spudland with the 373. Doc

 

[KBennett]

I have the 555 motor with 3. 73's and I have gotten 21mpg if I keep it around 65. At 75 it drops to 18 or 19. Towing at 70 mph I get 13mpg.

For some reason I get better mileage if I leave the cruise control off and use my foot.

I would think that a replacement gear set would be cheaper than a new truck. Is a 3. 55 gear available yet?

 

[Torque King Jay]

I did some testing last weekend on my way from Cincinnati down to Lake Norris in Tennessee. I went down there and had the cruise set at about 75mph. I got 16. 9 mpg. I filled up and ran it back at 68mph and got 18. 4. I drive some country roads and a little city to get to work and I've averaged 16. 5.



I definately notice a difference once I start turning more rpms on the motor. I still only have about 9000 miles on the truck after a year of owning it and I never tow anything so the motor still has some break in time.



Jay