14 tahoe 4x4 poor fuel mileage help

[dirtymax6610]

I'm not sure what to tell you, but in my experience when you deviate from OEM as-built specs, you're bound to have a negative change in mpg (not all the time, but there is usually a trade off for more power, etc). I'm not sure what affect the VVT delete has on these motors. There are MANY workings in the ECU on these motors that all need to work together properly.

Do you live in a cold climate? We're the catalytic converters deleted or replaced? What was the original issue that prompted thr rebuild?

Live in baton rouge so its warm down here. Cats were replaced with a oem set from walker. The issue that prompted the rebuild was i had oil running out of the throttle body. Then about another quart or so in the intake manifold.

 

[dirtymax6610]

That’s odd my 07 Tahoe with 400,000 even with a large vacuum leak and misfire would get 13.5-14.5mpg with a 9” lift and 26x14s on 35s
My 14” lifted Silverado on 14 wides and 35/15.50s would still average 14-15mpg

I knew with the cam i would loose a little mileage and that 23mpg wasn't that realistic. but i was hoping for at least the same 16 mpg her old one was getting.

 

[dirtymax6610]

I get about 9.5, the biggest factor is the big pedal, but she is not going to get 23

Figured 23 was not that realistic but was hoping for at least the same 16 mpg her old one was getting.

 

[dirtymax6610]

His wife can't be driving badly to get 16mpg on their old tahoe!

Currently at 8.8mpg 8.7mpg, maybe somethings wrong..
but I frequently use E85 and all short city driving.. And I don't drive super slow..

But I find 23mpg a little hard to believe..

I was just hoping for 16

 

[dirtymax6610]

Engine bored out, VVT deleted ... neither of those things help MpG.
Find a different tuner, have him sit next to you,
while the laptop is recording realtime data during a lazy, low-load, non-enthusiastic drive.
It may not be a tuning issue, but this provide better info than we can come up with.

Was dod and vvt deleted. Engine wasent bored , just a hone job .

 

[dirtymax6610]

Look at the fuel trims with a scanner in live data to see if they're within an acceptable range.

What octane fuel do you run in it?

Is it being driven in 2wd mode most of the time?

She run regular in it. Has not been put into 4wd since the build. And she drives mainly hwy for work.

 

[dirtymax6610]

a lot of times guys quote highway mileage after swaps and mods. mainly because stop and go city traffic mileage goes to crap. especially if you have to idle a alot with a cam.


just for reference, if she drives it in soccer mom hell like mine, even the hybrid tahoe don't get real world 20mpg, especially summer ac blasting sitting in school pick up lines type of crap.


I think an honest real world daily city driving almost 13mpg is really pretty good for a cammed out truck.


but yes, check your fuel trims might give an idea.

I could understand it if it was a large cam. But the texas speed cam is only 2 sizes above stock. So idk

 

[dirtymax6610]

I bet i could get it down to 7.5 lol

I bet i could to by dropping that 2.9 whipple i have on the shelf on it....lol

 

[dirtymax6610]

Dose anyone think that moving down to a 20 inch wheel from the 22 and maintaining the 33 inch tire size will change anything on fuel mileage ? Or should 1 go with a 31

 

[Trey Hardy]

I knew with the cam i would loose a little mileage and that 23mpg wasn't that realistic. but i was hoping for at least the same 16 mpg her old one was getting.

My old stage 4 cammed 5.3 I got around 15-16mpg on a 7.5” lift and 35s never highway drove it so that was around town on the highway she probably would have gotten around 18 maybe