ok dont drive the newest truck or the smallest but 8 mpg seems low. i got a 2000 tahoe with the 5.3. major modifications are the exhaust cold air and 35in tires. no codes being thrown by the computer completly lost on what to do. and yes i have done a full tune up.

 

You need a Tune...
Also, has the computer been calibrated for the 35s?
The tune will be well worth the money. I went from 12mpg to close to 15mpg with my blackbear. I'll hit 15mpg soon. I'm just having problems with my intake right now.

 

bought vehicle with lift on it no tune or reprogram that i know of. what do you all recomend for this.

 

www.blackbearperformance.com

Justin is very easy to deal with. And the tune is well worth the money. He'll email you a list of questions, then you answer them and email them back. Theres discount for military and first responders, cops and such.

Is your speedometer way off?

 

using the radar guns at work it seems about 4 under under 45 and 8 under at every thing over that.

 

How are you calculating your MPG? Your odometer is way off. Your bound to be gettin better than 8. What gears do you have to?

 

i belive they are 3.73 is there a vin decoder to check for theses? i get about 180 miles per tank according to my tripometer. i just emailed the guys at black bear maybe they will be able to help me out on this.

 

Blackbear is awesoem, I can't tell ya enough. Check your RPO codes in your glovebox for the gears. I'll find you the link to decode the code. if your running 35s, you want 4.10s at least. It will help your entire 'Hoe out, less strain on the drivetrain. Doing a gear swap ain't cheap, gonna be at least 2k on a 4wd.

 

Gq1 -- axle rear, std ratio
gt4 -- axle rear, 3.73 ratio
gt5 -- axle rear, 4.10 ratio
gu4 -- axle rear, 3.08 ratio
gu5 -- axle rear, 3.23 ratio
gu6 -- axle rear, 3.42 ratio
g80 -- axle rear, limited slip (positraction)

hc4 -- axle rear, 4.56 ratio

 

that link woeld be great thanks man. got a quote from 4wheel parts here in colorado springs for 1300 front and rear. with military discount.