Engine/Transmission (1998.5 - 2002) 2002 owners w/4x4 non-axle disconnect--what mpg?

[Hohn]

My truck is a July-built (late) '02. I have no disconnect. When stock (and not broken in) I got 16 city, 19-20 hwy (at 75). When I upgraded, my mileage change was not detectable. I mean, I got a little les when I was smoking for fun, but same driving meant sime mpg.



I also have a Mexican truck-- and I think it's great. I also have the Mexican block-- a very stout piece.



George, your low MPG is a real mystery to me. I bet you could throw all kinds of parts at it and not find the problem-- boxes, injectors, valve adjustments, timing variances, cam swap, etc. .



It might be just worth your while to get Piers or someone from his shop on the horn and see if they have any ideas.



HOHN

 

[geusterman]

Good idea, Hohn. geusterman



PS Why me ? I will get to the bottom of it eventually. Time and money.

 

[RowJ]

Revised figures

Truck was still pretty new to me when I last posted. Just finished longest highway trip, empty, 75 mph all the way. averaged 19. 5 mpg for the 370 miles with only 1 stop. As my foot gets heavier, my mileage gets lighter (and more realistic).

 

[geusterman]

Thanks RowJ. (Yer killin me) There is a goal for this truck and you set it. Talked with Mark at Piers Diesel and he suggested a reflash of the ECM. Also cleaning the MAP and IAT sensor as well as checking for a boost leak (got some smoke at night in following headlights). Also we heard on this list of a valve adjustment helping as well. Mark also said that heat is an issue and if I cruise too slow (rpm) the engine may not be hot enough to be efficient. Something to watch but probably not relevant here as the GV is a new addition. So now I need to unplug the EZ and schedule an appointment... . geusterman

 

[Pit Bull]

Originally posted by geusterman

Pit Bull, are you stock? George Eusterman

Totally stock. I have gotten as low as 16 mpg on the highway one direction and then close to 20 mpg driving home. This was on a 360 mile round trip. I think the wind had a lot to do with it and the speed I was driving. Last trip it was 20 mpg up and 18 mpg home. I also know that quality of fuel makes a big difference, try using different stations.

 

[time1]

I now have a 2002 3500 with 3. 54s and Auto Tran. and no disconnect for the front axle. Have 18000+ miles now and have not come close to the mileage of my old 1999 2500 with 3. 54s and a manual 5 speed with the disconnect. Both the 2002 and the 1999 are bone stock.



Worst mileage with the 2002 was 9. 9 with a head wind going west to Larame, WY pulling my 5th wheel (about 8000 lbs. ) this last July. The best mileage has been 19. 2 in and around Yellowstone NP and Teton NP. All out of overdrive and 45 to 50 MPH and light load in bed (about 1200 lbs. ) Total overall mileage 18000+ miles is 14. 1.



The old 1999s worst mileage was almost the same at 9. 8 mpg with the same 5th wheel and the same stretch of Interstate 80. Its best mileage was 24. 6 mpg driving around in the same national parks. Over all mileage for the 68000 miles I put on it was 18. 6 mpg.



I know that the 2002 weighs more because of the training wheels and being a 1 ton unit and I expected less mileage with the Automatic but I did not expect 4 mpg less mileage. Two good things about the one ton with duals is the way it handles the 5th wheel and the Auto transmission is great for backing the trailer in to camp sites. The best is that the wife will pull the trailer and let me rubber neck.