Mpg on 5.3 cammed, longtubes, tune

[skaffy03]

Does 14mpg (highway) and 11-12mpg(city) seem right for a 2004 tahoe z71 with a 212/218 cam, longtubes, and a black bear tune? I need retuned for headers but still... I also have 285/70/17 BFG ATs

New O2 sensors btw. Can't find vacuum leaks anywhere, either. Can't find any exhaust leaks.


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[Big Buttons]

Thats a little low imo. I get 13-14 city 19-20 highway. 219/227 high lift cam. And I drive it like I stole it.

 

[skaffy03]

Any ideas to get it going right again? Tranny has never been replaced, old fluid. Not slipping. Diff fluid never changed either.

I can't find any vacuum leak but I'm starting to wonder if I should just go ahead and replace my intake gaskets? Maybe low fuel pressure?


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[afpj]

Clean maf and tb. You sure the new O2 sensors working?

 

[skaffy03]

Maf is clean. Tb is clean. I got the shit Bosch o2 sensors but it's getting the same mileage now with the new sensors as it was with the old sensors.

Maybe dirty injectors? 167,000 miles on them


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[afpj]

If you got a bbtune assume you did the other tune stuff like plugs etc. May be to.e to run a few sequential bottles of techron cleaner. Hopefully a tune for the headers makes some improvement. Good luck.

 

[ccapehartusarmyINF.(ret)]

okay actually yer pretty lucky as fuel economy goes avg for an 02 tahoe is 14 mpg and thats stock and the dealer sticker says 13 city 18 freeway according to fueleconomy.gov
the average owner gets 14 mpg 13 city and 17 freeway and thats stock
and cmon dude 2002 suburban 19/20 highway mpg in yer dreams the mileage on the dealer sticker is 13 city 18 highway wich we all know is slighty exagerated
even the new ecotech granola friendly gaurunteed to save owls 5.3 liter v8 in the 2015 is claiming 16 mpg city and 23 highway
so sorry a 5.3 drastically modded with a cam getting 19 to 20 mpg im gonna call BS and i dont care if jesus christ himself did the tune.
technically drastic mods shouldnt hurt your fuel eco that much the biggest problem with fuel eco after you mod your motor is the driver

 

[Big Buttons]

I'm sorry you feel like I am lieing but that is what I have gotten. I got those results twice when I really wanted to see what it could do. I don't normally drive like that though. When I drive like I usually do it's more like 12city 16-17highway

 

[mattluttrell]

I have an 02 Escalade with the 5.3 and about the same miles. I can get close to 20 (avg 19) mpg on highway.

Yours does seem a bit low.

 

[mikeyss]

What gears do you have? My '05 hoe has 4.10's and I barely get 13 city and 17 highway.