Engine/Transmission (1998.5 - 2002) Fuel Mileage

[91W350]

I know that it depends a lot on how we drive our trucks. I have a 91 that usually runs around 20 to 23 on the highway. My 03 4x4 usually runs very close to 20 on the road. I normally set the cruise at 65 to 68 mph. Wind seems to really punish the 03. On a trip across Northern Nebraska the 03 made over 25, but that was 55 mph with no stops for several hundred miles. I know several of the guys have experience with all of the Cummins engines, do any of them stand out as fuel mileage kings? I have read that guys with the 24 valve engines get mid 20s for fuel mileage. My son is already in the process of stealing my 91 and my wife has stolen my 03. I am leaning towards a 24 valve HO quadcab manual as my next truck. Thanks for any opinions. Glen

 

[Oil Burner]

FWIW,



stock, my 24v ETH got about 17 in town and around 19 highway. Stage II injectors brought it to 18 in town and a best of 23. 5 across ohio at a steady 70 mph.



These Jammer 4's have given me a steady 19 up to 21. 5 on daily driving and I haven't had them on a long trip yet but they should beat the old IIs.



This is with stock street tread tires and 3. 54 gearing. NO timing box, just a boost fooler.



Thanks,

Jason

 

[Mike760]

I have run 23-25 mpg unloaded on thrips from socal to Vegas. It is about 230 mi from here to Vegas and I can easily make it there and back on 1 tank including about 100 miles of driving within Vegas and then some.