ax, you must drive like a little old granny if you can't get below 15.4 mpg while pushing it.

 

2007 NBS 5.3 - GETTING 19-20 ON DRIVE TO WORK - 30 MIN DRIVE BACKROAD COUNTY 40-60 MPH

 

Are ya"ll using the onboard computer for these figures? It's been my experience that these are about as accurate as throwin a rock in the dark with your eyes closed. My Dodge Ram 3500 computer shows an average of 34 - 38 mpg. It actually gets 20 average.

 

Ok rstank on my triphome from the track Sunday my Silverado computer said 18mph & then my caculator said 18 mph so I guess dodges computers can't be trusted!

2007 NBS 6.0L GM cold air & 3:73 gears

 

I just took a trip this weekend 374.6 miles on 16.43 gal of gas = 22.8 mpg, first 150 miles was highway (50-70mph with cruise) second ~ 50 mi was city, then 170 mi home (50-75mph with cruise)

I took pics with my cell phone:
http://img.photobucket.com/albums/v206/gitarkid/File00091.jpg
Odometer: 43.1 mi, gas gauge, almost at F

http://img.photobucket.com/albums/v206/gitarkid/File00093.jpg
Odometer: 287.7, gas gauge just past 1/2 (that was after the city driving)testing

Also, the last 1/2 of the trip I had a stove and washing machine in the bed...

 

YEP I CHECK IT EVERYTIME I FILL UP - THE AMOUNT OF FUEL USED ACCORDING TO THE TRUCK AND WHERE THE PUMP KICKS OFF IS WITHIN .25 TO .50 A GALLON OF EACH OTHER.

 

Also, does anyone else's gas gauge seem to "drop off" after 1/2 a tank? Like the first 1/2 tankI can get about 115-130 miles per 1/4 tank, but from 1/2 to 1/4 left it seems like I can only get around 70 mi 1/4 tank. I'm wondering if this is because of possibly the tank not being a "regular" shape and the gas guage using a linear gauge to estimate what's left.

 

yep can go forever on 1st half of the tank and then like 2 days on the second half.

 

Usually, a cold-air intake, headers, or even keeping the tires at the right PSI will improve the gas mileage of ANY vehicle. I've seen some posts on this site about converting your vehicle to a "hybrid", but it looks pretty expensive. I found an Option Racing cold air intake system on e-bay for $80 and a set of Flowtech headers online for about $200. That's where I would start first.

 

I have a 2003 2500hd 6.0 with 285 75 16 aggresive tires, because i use them, and my truck averages 7.5MPG. I run it, when i want to go no holding back. Its a great work truckandit will haul a load but the gas milage SUCKS.