LBZ Fuel Mileage

[Barkbuster]

Took a 460 mile trip with my dirtbike in the back @65-70mph 18.8mpg. 3500 on the truck now. Usld may be hurting it a bit. really bummed it didn`t get over 20 on this trip

[up@12]

I have 35,000km on my 06 duramax and am getting 17-18 mpg but was getting alot better when I first got the truck. I think I need to beat on it for a bit. LOLOL

Sorry I am getting 14.6 MPG I typed the wrong thing. But in saying that last night I took out my AFE filter and put in my stock filter and with the AFE filter I was getting about 122km to a quarter tank now with the stock filter I have 122 km and it has just moved off the full mark. Anyone else ever have this?

[Barkbuster]

Best week yet! 19.3 no highway just to work and back

[Zacc]

Does anybody know what the gas engines get for mpg? With diesel costing over 50 cents more per gallon it's tempting to look to the underpowered option.

DZ

[Barkbuster]

I got to try a hybred GMC while mine was in for service and used it to go to work for a day. I reset the dic and got 20mpg to work but coming home dropped the average to 18.3. Had the 5.3 with electric assist and was not bad. peppy performance but not as much power as the diesel. Was weird when the motor just shut off at traffic lights. As soon as the brake was released it was running again. the diesel is also less noisy.

[Lawrence]

Just breaking in my 2007. 330 miles on it now. Filled the tank at the half-way mark. In mixed driving and during break-in I averaged 15.8 mpg. A little less than I'd hoped for, but I am sure it will improve as things get seated.

Can't wait to see how it pulls our toyhauler!

[8lug]

Boston to Auburn, Me. 225 mile round trip. 70-80 mph dic says 17.5mpg. i got 2200 miles on my truck so far. 07 gmc cc longbox stock. When i drive in bumper to bumper traffic all week it get 14.50

[Barkbuster]

Temps took a plunge around here this week and so did my milage! 15.7 driving in 0 to 20 degree temps last week. The warm-up idling I did while putting the tractor away as I finished work hurt the milage more than the cold I suspect and I won`t be doing much more of that anymore,

[JohnC]

Temps took a plunge around here this week and so did my milage!

Our distributor started delivering 20% winter mix last week....

[Barkbuster]

Haven`t used the truck much since the cold snap last month. I checked tire presures before xmas and all were around 45psi. I reset to 60psi front and 50psi rear and the ride got a little stiffer but the milage got much better! 19.1mpg, my 2nd best tank so far.

[Kennedy]

I need to check my tire psi also. Glad you mentioned it!



My 07 wants to run at upper 15's at 72mph and upper 17's at 62 mph. I have been playing with ECM tuning and had it running at 20-21+, but the short hops, varied conditions, and warm ups knock me back down opn average. It is definitely encouraging and I see definite gains from tuning, I just need to collect more data and refine the tuning a bit more. DIC appears to be dead nuts on so long as I stay away from the pulse width tables.

The truck only has a few hundred miles on it so far and I need to get my usual SS cold front for it soon.

[SoTxPollock]

John, do I understand correctly that your EFI Live works with the 07? I thought they were 32 bit processors instead of 16.

[the_croz]

2006 3500 WT, 1LT, Chassis Cab. 161.5" wheel base, 84" cab to axle, LBZ W/ 6sp Alison, 3.73:1 gears, 215-85-16 with less then 3,000 miles on the clock.
I just took a 300 mile ride @ 75 mph.. got 12.8 mpg and @ 80 mph got 12.6 mp. I'm happy..

[Sea-Air-Ahh-LBZ]

I am new here only one tank of #2 through the 07 GMC Sierra 2500HD ext cab LBZ motor. All fwy. Buena Park up Cajon Pass to Victorville back to Laguna Niguel. 16mpg DIC 17.5mpg caculated at fillup. avg. speed 70-75. I'm like-n-it !

[mschuyler]

My son in law reported over 21 mpg on a road trip up I-5 from San Diego to Seattle. That's about a 1400 mile run. Crew Cab 4wd long box.

[DieselMonk]

First time I ran a whole tank of fuel through my 07 Classic, Crew cab, long box. Short distances only (nothing over 10km on the highway) lots of cold starts, winter front off and I got 18L/100 on the DIC, but 16.9L/100km hand calculated. I used to do same route with my old truck and a 6.0L gasser and averaged 22.5L/100km. That is 5.6L/100km less fuel used and the new truck isn't even broken in yet. Not bad at all!

[Prestonia24]

I've just passed the 7500 mile mark (270 engine hours according to the computer) in my truck. (purchased almost 8 months ago), and have been seeing progressively better mpg gains.

I tend to drive about 200-300 miles a week in my truck depending on how many trips to the GFs house I make (shes in laguna beach aka 44miles each way). Depending on how I drive ill get between 16 and 23mpg on the fwy and 12 to 15 on streets.

upon my last trip to vegas in december I did a test on fuel mileage.

on the way to: 290mi, avg speed 80-85mph. fuel economy (hand calc) 13.2mpg.

the way back: 291mi, avg speed 67mph (1800rpm). set the cruise control, even over the cajon pass. fuel economy 22mpg. made it on a half tank....
(before the pass the dic estimated economy was 23mpg, and its spot on)

moral of the story. keep it under 75 and save some fuel.

-Cam

[larryh1]

I have 5,000 miles on mine.....I am not heavy footed, mostly highway driving, usually drive around 70 to 75 mph. I cannot get better than 14.5. It has been the same on all tanks. I am very disappointed.
I just finished my first long pull. I have done some short ones to properly break in everything. I varied the speed between 55 and 70 during breakin. Pulling a 30ft toy hauler, 10,000lbs loaded, 500 miles. Speed - 65/70. 8.5 MPG!!! I am not happy at all!! Can I hope for better or do I need to make a trip to the dealer to check for a problem?

[cowboywildbill]

We are just comming up on 1,000 miles on our 07. I am only seeing 10.5 so far just short trips. I was seeing 15.5 and better on our 06 before it got wrecked. I hope this 07 does better. I'll blame it on winter and not being broke in yet. It is identical to the 06 except mpg wise.

[Dihrdbowti]

Well my DIC shows about 14 in town hand calculated it's 15 on average. Long trip from Reno to Victorville and back DIC showed 21 and by hand it was 22. DIC also shows that I have used about 1 gallon more than what i put in..
13000 miles 07 CC classic LBZ completely stock.