I've never put more than 23 gallons in mine, including filling the fill tube up. I've also never gotten any better than 400 miles to a tank, including when it was stock. I think my truck sux for mpg.

 

Im with you one this one. /2 cents/

 

I don't work far from home just about 16 or 17 miles so about 32 or 34 miles a day @ around 70 mph, also I only start the truck twice( in the morning and going home). I only fill up the tank up half(to reduce weight) to 13 gal, 2 gal being the reserve so @ just over 200+ miles a week I think my avg is just about 17 or 18 mpg.

 

I once got 21mpg round-trip in my HD driving all the way across Houston and back. A/C on, cruise set at 75, and the only hills were freeway overpasses. Granted the setup on one leg of the drive was perfect: stout tailwind pushing me, the only time in human history where traffic through downtown Houston was flowing well enough to not make everyone slow down for some unknown reason, and oh yeah, my transfer case was actually working. The other leg wasn't so great, but I didn't have to slow down too much below 50mph, I was still doing around 70mph for most of the drive. I still couldn't believe it though, a stock tired, 4.10 geared LQ4 4x4 with a toasted NVG-261 got 21mpg. I average 12 in the city due to my transfer case having so much slack in it, but with a consistent speed, the truck does decent (read: 17-18 highway normal).

Also I checked my mileage the old fashioned way (since I don't have the little mileage calculator in my base model truck): filled up with the same pump at the same station with the same method; then compared the amount of gas used against the miles driven.

Tom

 

i get 11.5-13 constant, 15 pure freeway. i suck gas. that was with the ls6 cam, im insterested to see on the new one.... im scared. hopefully after the efans itll get a little better. i struggle for 300 miles on one tank

 

I posted up the calc_pids.txt file for it in this thread:

http://forum.efilive.com/showthread.php?t=1667

Post 27 has the file.

 

14 MPG combined city freeway. 15.5 on the highway. 6.0 Vortec Max. I don't see how people are getting 20 + MPG with a 6.0. It has not gotten 17 MPG like the sticker on the window said. I think people need to take a refresher course in arithmetic.

 

Hard to believe isnt it?
and its a 4x4
Its possible the red ones were not going to get decent fuel mileage.

 

yea the dealer says red paint weighs down the trucks waaaaay to much to get decent mileage.....

 

My dealer said the same thing,the pigmont in the paint has more drag.