eatapeach

Ok....I need some help with understanding why I dont get anywhere near the MPG that I read majority of you get. I have a 07 5.3 with G80 3.73 and a 93 octane BlackBear Tune. I drive about 60 miles a day and 80% of that is highway and I get 12-13 mpg or roughly 280-295 miles per tank. I recently took a trip to Lubbock from Dallas, 360 miles, and couldnt make it there without filling up about 30 miles outside of Lubbock. On the way back to Dallas same story. WHY??

I know what some of you are thinking and no I dont have a lead foot. My girlfriend is constantly on my *** for "driving like a granny". Expect I run 75-80 when on the highway.

I have been holding off on any other mods because of fear it will get worse.

Any help...ideas?

BlackGMC

iTrader: (31)

what size wheels/tires are you running?

eatapeach

forgot about those....22" with 305 40's

Razorback Randy

I was getting 14-15 in my 5.3L 4x4 extended cab. The best I ever got was 19 when the truck was brand new with factory wheels and tires while driving on the highway at about 65 MPH. All of that was without any tune and running 87 octane.

skoal bandit

iTrader: (1)

12-13 blows. with the mods in my sig and flat footed at every stop sign and red light in the city for a whole tank of gas, i got 13.5. maybe talk to your tuner and see if they can check it for you. something not right.

BLACKND

iTrader: (5)

Damn, I average about 16-17 in my 4.8/3.73's. I've gotten up to 22-24 on pure highway runs. What were you getting before the tune?

eatapeach

Thanks for the replies.

Skoal, I agree something isnt right. Dont get me wrong it runs great...better than most tune only 5.3s, CC with 22s, that I have driven/ ridden in.

L33Z71, I cant say for sure what I got beforehand bc I bought it used and only ran 1 tank through it before tune but I think I remember getting almost 400 miles on that tank. At the same time a buddy of mine had the same exact truck just different color and was getting 450-470 mpg on road trips to Colorado and his was Tuned by Black Bear as well.

Guess I need to get in-touch with Justin.

eatapeach

Also, do yall have the 4L or 6L tranny? I forgot to mention that I have the 4L. Would it be worth it to switch to a 6L?

Preston129

iTrader: (3)

I get around 12.2-13.2 mpg with about 90% city driving. Once did an experiment and drove to Ogdensburg trying to stay in V4 mode as much as possible and got 20 mpg. Not great, but it's 5000 lbs of truck that does a lot of stop and go.

BLACKND

iTrader: (5)

Mines got the 4 speed auto