Chevy and GMC Duramax Diesel Forum banner

lbz mpg???

44K views 146 replies 82 participants last post by  robphillips00 
#1 ·
What are you guys with the lbz's getting for fuel mileage? When i bought my truck about a week ago i was getting between 16 and 17 mpg. Yesterday i did about 150 miles of moderate towing(nothing very heavy) and dropped down between 12.5 - 14 mpg on a bone stock truck? i really expected better fuel economy with this truck.
 
#3 ·
alright, thank ya sir, glad to know nothin is wrong.
 
#4 ·
i was getting 14 to 16s if i was lucky before all the adds, with the exhaust/ down pipe/ programmer i get roughly 17 to 19. Trying to figure what to upgrade next to help with my miliage:gearjamin
 
#5 ·
I get about 19 out of mine empty, I pulled a cattle trailer on I44 in Missouri and got 17, it was empty though but I thought that was pretty good.
 
#7 ·
Truck will do 20 or over but I do too much stop and go or drive too fast on the highway to get a whole tank over. My average is roughly 16. Best tank to date was 19.2

Sent from my Incredible 2 HD using AutoGuide.com App
 
#8 ·
damn my truck gets way better milage. i filled mine up and so far i used a half tank and the trip od says 330 miles and i still have half a tank left. thats no towing and avg 60mph with a bunch of burnouts and raceing around a little.
 
#95 ·
Yeah but we all know that sucker drops like a rock after that prolonged first half tank....you'll get 400 +/~ like the rest of us stiffs ha ha


Sent from my Galaxy S2
 
#11 ·
That sounds about right, with exhaust restrictions and lack of tuning. I average 19 MPG hand calc with my mods
 
#12 ·
how can i get such great milage and u guys dont? i bet if i was really nice to the right pedal i could get almost 500mi to the tank.
 
#14 ·
how big is your tank?
 
#15 ·
I just bought my lbz last saturday. Drove from Portland, Oregon to Northern California, 8 hour trip and averaged 18 and some change. Went to Reno Nv earlier this week round trip couple hundred miles and got 19.07mpg. Averaging about 15 in town stop and go. Probably do better if I could keep my foot out of it. Oh, all hand cal.
 
#106 ·
I get 18-24 highway depending on how heavy my foot feels :) going 80-90 to lake powell :) I also tow a 40 camper 5th wheel and get around 9-12 mpg goin 75-80 efi live helps


Towing at 75-80?

So, did I read that wrong or are you are willing to risk your safety as well as the safety of others towing a 40' trailer?
 
#21 ·
I get 18ish daily in the city and about 24ish on highway with mine. When towing a small camper or my atv's with trailer it only dropped to 17ish.
 
#23 ·
12 at 80 with 40.....haha:
nono
 
#25 ·
22-24 highway, lately around 18.5 city

.
 
#26 ·
been averaging 21 on the highway hand calculated. I'd like to know how you guys are getting upwards of 21+. I have exhaust efi live and 245's still but can't get any better than 21.
 
#28 ·
Speed, driving style, fuel, fluids, tires, pressures, truck height, etc.

Keep top speed down and maintain speed with cruise control if possible, any extra acceleration or braking wastes fuel. It also helps to coast as long as possible before stopping....minimizing brake use.
Definitely do not idle any more than necessary, that KILLS MPG.

.
 
#29 ·
Mine got 19.6 last road trip I took. I was running 75-80mph on the interstate to Tucson. In town it gets between 14-16 depending on how much stop and go I encounter.
I tow my 27ft camper and only hit 14 if I stay under 70. In a gasser it would be 8
 
#30 ·
I've been doing a good bit of designated driving with my beast here in downtown Athens. lots of hills, stop and go, and a heavy right foot on the 120 tune put me at well under 10mpg. think i'm going to start driving my tow tune or 70hp tune in the city. lol.
 
#32 ·
I just got thru pulling a 23 foot camper trailer 45 miles one way, my DIC said i averaged 12.8mpg. I made the same trip not pulling anything and my DIC said 18.3 average. Max speed was 65-70mph.
 
#34 ·
Bone stock, '06 GMC classic, extended cab, low miles.

12-14 mpg towing
15 mpg town/city
18-20 mpg highway < 75 mph
15-17 mpg highway > 75 mph

Summer blend diesel, winter blend drops 10-15%.

I'd rather leave it stock since I don't use it as a commuter or daily driver.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top