Duramax MPG Thread
Diesel Enthusiast
Joined: Jul 2008
Posts: 110
Likes: 6
From: edmonton ab canada
my truck is stock and empty and driving sane i get 650 - 750 miles out of a tank
i use diesel clean with cetane boost every tank(in the grey bottle). and my rig aint no reg cab short box
on secret is to keep your mass air flow sensor clean i use a good carb cleaner i do that every oil change. make sure it evaporates and doesn't leave any deposits
i use diesel clean with cetane boost every tank(in the grey bottle). and my rig aint no reg cab short box
on secret is to keep your mass air flow sensor clean i use a good carb cleaner i do that every oil change. make sure it evaporates and doesn't leave any deposits
Super Moderator
Joined: Oct 2007
Posts: 14,872
Likes: 764
From: Houston, Tx
oh yeah, the MAF is very important to keep clean,
it can be a real hassle if you have an oiled aftermarket filter. it can cover the sensors with oil and your MAF will give false readings back to the ECM. End result extreme turbo lag and loss of mpg, and not as responsive.
it can be a real hassle if you have an oiled aftermarket filter. it can cover the sensors with oil and your MAF will give false readings back to the ECM. End result extreme turbo lag and loss of mpg, and not as responsive.
have a tube that keeps coming off like mine i need to find a new intake tube that is either longer or get new boots that are longer i have to check mine almost everyday. you could try what this guy does its called hypermileage i saw a clip on a show about this once they used a that little Pontiac sports car
Last edited by jdugie123; Jul 28, 2008 at 12:40 PM.
BOMBARDIER
Joined: Apr 2007
Posts: 6,804
Likes: 319
From: Houston, Tx
24 is really pushing it. 27?? NO WAY. The only way that happened is that he was driving down a mountain. I average 21.5 on the freeway at 75 mph and 15 in town. I sit in traffic for 2 hours a day so my in town mileage is going to be low. 650-750 on a 26 gallon tank. NOT HARDLY. You're trying to tell us that your getting 25-29 mpg??? Might wanna call GM...you've just performed a miracle. 
Diesel Wrench
Joined: Dec 2007
Posts: 971
Likes: 41
From: Houston, Tx
Not to jump on the bandwagon, but I have to agree. Even with stock tires, 27 is not going to happen. Double check and hand calc your #'s. If you found a way to get 27 with real world driving, you will be wealthy very soon when you sell your secret.
BUT melted a few pistons in the mean time 
Just an FYI.......
Diesel Enthusiast
Joined: Apr 2008
Posts: 286
Likes: 10
From: Amarillo, TX
My 03 LB7 gets 22-24 mpg with about 20% in town driving at 70-75 mph. Pulling a 40 ft trailer empty is 15-16 and loaded grossed out at 45k it gets just over 10.
I have 5in straight exhaust and other than that I have no other upgrades. I do use a additive called Howes Meaner Cleaner, which I swear by. Maybe the 6-spd helps out a little too.
I have 5in straight exhaust and other than that I have no other upgrades. I do use a additive called Howes Meaner Cleaner, which I swear by. Maybe the 6-spd helps out a little too.
Last edited by KuNtRy BoY; Jul 28, 2008 at 06:21 PM.
Diesel Wrench
Joined: Apr 2007
Posts: 988
Likes: 55
From: TX
24 is really pushing it. 27?? NO WAY. The only way that happened is that he was driving down a mountain. I average 21.5 on the freeway at 75 mph and 15 in town. I sit in traffic for 2 hours a day so my in town mileage is going to be low. 650-750 on a 26 gallon tank. NOT HARDLY. You're trying to tell us that your getting 25-29 mpg??? Might wanna call GM...you've just performed a miracle.
