LBZ: Lbz fuel mileage build?

Bustedknuckles

Honey Badger
Sep 25, 2010
1,308
2
38
33
Hagerstown MD
07 ccsb 4wd with a built engine and trans. We are looking to get close to 25 mpg highway out of it.
I'm thinking a cheetah, 15% injectors (needs new ones anyway), Idaho-rob tuning and cng injection. The truck has 285s, a airdog, torsion bars bottomed out and 3" drop shackles in the rear.
What would you all do differently and is it possible to get 25 mpg interstate with out stupid looking areodynamic mods or CNG?
 

Bustedknuckles

Honey Badger
Sep 25, 2010
1,308
2
38
33
Hagerstown MD
I didn't figure it was easily possible on fuel only, there's a guy on Compd getting 32 mpg out of his 12 valve however...... What about CNG? Anyone on here run it or know who I need to talk to to buy a system?
 

LBZrcks

.........
Jun 2, 2007
5,297
12
38
38
SoCal
07 ccsb 4wd with a built engine and trans. We are looking to get close to 25 mpg highway out of it.
I'm thinking a cheetah, 15% injectors (needs new ones anyway), Idaho-rob tuning and cng injection. The truck has 285s, a airdog, torsion bars bottomed out and 3" drop shackles in the rear.
What would you all do differently and is it possible to get 25 mpg interstate with out stupid looking areodynamic mods or CNG?

Non vvt turbo.
 

blk smoke lb7

<-----Lots of green $
Nov 8, 2010
5,694
0
36
57
belvidere,ill
Gm's idea of dumping fuel in to clean the dpf doesnt help thats whre the delete and the efi live can help bring it back.Also dont even mess with cng it sucks we used to run our fleet vechicals on it and the tank took up a good protion of the bed and we could only get about 70 to 90 miles on it (running full on not just adding to gas).If your thinking on going to this go propane and get the underside mounting tank that goes where the spare tire is under the bed but after you factor in the cost and pain in the ass of filling the propane tank it may show better fuel milage but at what cost?Get the truck as low to the ground as posible use the lightest wheels and tires spinning mass is a killer,lightweight the truck as much as possible.Also look into brown gas or hydrogen you can make your own fuel rolling down the road with this and the cost is minimal but because its water you cant really do it in the winter in cold climate.I have heard of claims of 30 plus mgp (CLAIMS I SAID) Depens on the size of tank and how much gas you can make.
 

LWATSON

future trans limpers
Jul 30, 2008
2,587
1
36
55
Scotland Neck NC
Its going to be hard to get 25 mpg on the interstate. With my stock turbo I could get 24.5 hand calculated with my old economy tune at 55 mph. If I bumped it up to 60 mph my mileage droped to a little better than 21. 65 mph and it was around 19.5 and pretty much would do that up to 70 + or - . Wind resistance is a killer. Normal day to day driving I got around 19 mpg.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
found some interesting info on smaller tires, from the prius bashing thread...

http://www.cleanmpg.com/forums/showthread.php?t=41702&highlight=tires

post 7. any thoughts here?
There may be something to that. I went from 285's to 315's, and gained 1 MPG highway. Lost a ton in the city, but I was expecting to loose MPG all the way around.

Non vvt turbo.
I would think a good VGT would actually be beneficial to mileage, as long as the tune was decent. I run ~4 PSI cruising at 70 MPH, and there is no reason for it. If I had a VGT and set it for 0 PSI, there would be less backpressure, and theoretically better mileage.

Is that why LB7's generally get better mileage?
They have a higher compression ratio
I think the compression ratio helps a lot, but I personally suspect that tuning is the biggest difference. Also, I think LB7's have the largest factory injectors-- if true, they can put the fuel exactly where it belongs easier.
 

Bustedknuckles

Honey Badger
Sep 25, 2010
1,308
2
38
33
Hagerstown MD
Hydrogen is a joke, I know that from experience! The theory is great but the amount of hydrogen needed to help cannot be produced easily, you would need huge tanks.