Promise i'm not a liar

DAVe3283

Heavy & Slow
Sep 3, 2009
3,729
297
83
Boise, ID, USA
I'm super jealous of you guys. Best I have ever gotten is 19.4 MPG, and that was all highway, 55-65 MPH. Fuel stats:

Does anyone elses low fuel light kick on right about the time their truck runs out of fuel? My low fuel light is a bit retarded
I used to have this happen all the time, and sometimes it would die before the light came on.

I finally got mad and pulled the sending unit, and found 2 things. One, the pickup tube was cracked so it would suck air, and two, there was a bottle cap stuck to the bottom of the pickup.

Threw a new one in and no trouble since!
 

hotdogstand

Member
May 27, 2013
35
0
6
Norfolk, VA
The best I've ever gotten is 25-point-something coming out of the mountains on the way west through WV/Kentucky. Averaged 21-ish on flat land on both sides of that, though. 1000 mile trip, probably 200+ miles between fill-ups.
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,214
364
83
At Da Beach
26 gallon for 2001-2010 short bed trucks.

I think GM lied to me though. Ive run my truck out of fuel a dozen times or so and never in 240k miles put more than 23 gallons in.

Yet some people claim they have put 25-26 gallons in their 26 gallon tank...so who knows. :rolleyes:

I put in over 24 several times in my lmm. The other day my lml took 35. I was pushing it...lol...
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,214
364
83
At Da Beach
Does anyone elses low fuel light kick on right about the time their truck runs out of fuel? My low fuel light is a bit retarded

Pull your sender and clean the fuel senders board and contactor with clr. The one in my lmm would do some funky stuff untill I cleaned it...

Also retension the contactor...
 

Lance LB7

New member
Nov 5, 2013
44
0
0
Kentucky
I get high mileage My self. The zf6 and reg cab plays a big part in it. Like the truck by btw:thumb:[/QUOTE]

Thanks man. but yeah single cabs and zf-6 helps a lot. its got manifolds and intercooler too, which probably doesn't hurt
 

LbZzF6RCLB

New member
Feb 4, 2015
39
0
0
Butler Pa
I know its hard to believe anyone on fuel mileage but these numbers are hand calculated and I wanna see if anyone else has ever seen these. filled up at home and drove to college, all highway and interstate. filled back up, 70 miles, and averaged 29.2 MPG. anyone else ever seen anything this high or is it a fluke?

I get high mileage My self. The zf6 and reg cab plays a big part in it. Like the truck by btw:thumb:
 

SickLL7Crenshaw

Billy The Kid
Mar 10, 2013
1,088
34
48
31
Mexico
My grandfathers feed pickup which is a shortbed lb7 the fuel gauge doesn't work and he forgets to fill it up before leaving the ranch sometimes and I always get the call that he's ran out of fuel. I've put in 25.2 gal before in that truck. And the tank was bone dry.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
Stock motor I averaged 13.5mpg. Built motor I average 13.5mpg. The absolute highest I have ever gotten in any of the trucks I have ever owned was my 01 24v cummins. QCSB 5 speed with an edge comp box, stock turbo and some edge jammer 5 injectors netted me 18mpg with cruise set at 71mph coming back from Vegas to salt lake.

I do not understand how people get the mileage I see so many people claim. My 12 valve got 12mpg. My 02 lb7 got 13mpg my 01 24v averaged 15mpg and my 05 lly averages 13.x in the winter and i can squeeze out about 14.5mpg in the summer.
 

catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
0
36
NE Oregon
I had calc at one time in my LLY with efi live tuning and stock turbo going from Home to seattle and since i was on OT the whole way I set the cruise at 65 and left it alone lol. 19.1 mpg it is up and down hills my 03 6 speed ecsb zf6 I got 22.3 driving back to colorado on one tank most the time that one would get 18 empty with nothing done to it at all.
 

WolfLMM

Making Chips
Nov 21, 2006
4,005
26
48
38
AL
26 gallon for 2001-2010 short bed trucks.

I think GM lied to me though. Ive run my truck out of fuel a dozen times or so and never in 240k miles put more than 23 gallons in.

Yet some people claim they have put 25-26 gallons in their 26 gallon tank...so who knows. :rolleyes:

Yup, the absolute most I have ever put in was 24.00 gallons. And I basically coasted into the fuel station.
 

jacobdewey

This won't last long...
Jan 14, 2011
972
0
0
Stock motor I averaged 13.5mpg. Built motor I average 13.5mpg. The absolute highest I have ever gotten in any of the trucks I have ever owned was my 01 24v cummins. QCSB 5 speed with an edge comp box, stock turbo and some edge jammer 5 injectors netted me 18mpg with cruise set at 71mph coming back from Vegas to salt lake.

I do not understand how people get the mileage I see so many people claim. My 12 valve got 12mpg. My 02 lb7 got 13mpg my 01 24v averaged 15mpg and my 05 lly averages 13.x in the winter and i can squeeze out about 14.5mpg in the summer.

The lowest I've ever got in a duramax was 13 mpg pulling my enclosed trailer from Idaho to Vegas. Used to go every winter, and mileage was always around that 13-14mpg. My rclb lb7 averages 16.5, and that's letting it warm up and idle alot. Most of my driving is 65mph or less though.
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
3,964
8
38
36
Goodyear, AZ
Lb7's are usually the best for mileage so take that into consideration.

I've never once put over 24 gallons in and I drove with the low fuel light on for 2 days back and forth to work :roflmao:
 

Awenta

Active member
Sep 28, 2014
4,090
2
38
CT
Lb7's are usually the best for mileage so take that into consideration.

I've never once put over 24 gallons in and I drove with the low fuel light on for 2 days back and forth to work :roflmao:

LOL that's brave. I set my alarm at 15% and don't usually get that low. I like to fill up at a quarter.

Picked up that habit after making a quick run to get something and then realizing there isn't a gas station anywhere within half an hour.

Sent from my SM-N910V using Tapatalk
 

Lance LB7

New member
Nov 5, 2013
44
0
0
Kentucky
The lowest I've ever got in a duramax was 13 mpg pulling my enclosed trailer from Idaho to Vegas. Used to go every winter, and mileage was always around that 13-14mpg. My rclb lb7 averages 16.5, and that's letting it warm up and idle alot. Most of my driving is 65mph or less though.

My truck at 55-60 will only get 20-22mpg. Rpm's are about 1600 at 55 and it seems like its kind of under the charger at that rpm so it has to work a little harder to maintain speed. and the pyro reflects that. at 75 you're turning 2k and the truck kind of pulls itself up hills. on the interstate pyro never gets above 800
 

Harbin_22

Active member
Dec 4, 2010
3,858
7
38
Southern Indiana
Guys that get bad mileage must have a heavy foot or shitty tuning. I just drove a built motor, 60% Inj, 72/83 compound set up, 1700miles in below zero temps from Louisville to Massachusetts and hand calculated over 19mpg between 70-80mph. I can beat the crap out of my truck, let idle a bunch and still never get worst than 13-14mpg.
 

DieselBulldog10

Go Bulldogs!
Jan 16, 2009
29
0
0
38
Oakdale, Ca
I have hand calculated 28.4 MPG over the last couple tanks of fuel. I do a lot of freeway driving though so that will boost it compared to a lot of people. About 5000 miles a month.

I couldn't believe the good mileage I was getting with it. Before it was tuned and intake was cleaned and all the other goodies the best I could do was 20mpg or so.
And I thought my old 12v got good fuel mileage. I was pleasantly surprised by this.