4.8 vs 5.3 questions

[Goat08]

Haha i wish i had that. It would be easy just to look up and see it but my truck didnt come with it

[RedHeartbeat]

Your dash panel on the left side of the wheel where the headlights are, you don't have the four button DIC panel to the right of the a/c vent?

[RedHeartbeat]

Here, buy one of these, remove your stock panel and reinstall this one. The wires for it are behind your dash panel.
GM Parts Direct: Your direct source for Genuine GM Parts

[Goat08]

Whats the little button for?

[zebra]

...2. Me and my buddy have the EXACT truck. Both 08 short bed regency after-style, with 275/55 20 wheels and tires. The only diff is he has a 5.3 and makes 15 mpg and i make 12 in the city. Thats with a K&N, shorty headers, and 93 octane tune from nelson. I also have a cutout and im testing that to see if it helps my mpg any. So what im asking is, why does he get better MPG than me?...

dude, my 01 5.3/5 spd just got 16mpg mixed on this last tank.
that's with 4x4, airaid, blackbear 93 tune, mellowtone catback. the real kicker was that this tank was mostly WOT runs (for filming exhaust comparisons & running dynolicious), 75-90 on the interstate (2 separate unavoidable issues that made me have to get to work fast), and some up/down shifting practice.

[Goat08]

Omg this is ridiculous. why is my MPG so bad? I mean yeah i hit the gas alot but why should it be any different than the next?

[RedHeartbeat]

Whats the little button for?

Little button? There is an opening for the headlight switch and the dimmer switch you have to transfer over from the original panel. The little button on the instrument cluster? About all its good for is trip setting. They swapped a set of GMC wheels onto my truck at the dealership and I automatically have 4 wheel air pressure sensors on the truck, not sure if the stock worktruck has them or not but they probably do.


Drive like there is an egg between your foot and the pedal and mileage will increase. Is your airfilter dirty? Do you have any engine codes? Could your cats be clogged?

[zebra]

...Could your cats be clogged?

i sure know mine ain't!! i've spent the past week blowing them out quite nicely

[Goat08]

About all its good for is trip setting. Is your airfilter dirty? Do you have any engine codes? Could your cats be clogged?

I already have a trip setting, i can use the little knob in my instrament cluster to set the trip timer just like on every other car. Thats how ive found out the MPG so far.

no engine codes, and if sound is any indication of cats being clogged then my buddys 5.3 is louder than my 4.8. I just figured it was his bigger motor. How to you test that out?

[RedHeartbeat]

FWIW, the DIC panel give you access to a whole lot more data than the trip meter button on the instrument panel.

testing for a clogged or restrictive cat takes a pressure gauge or a laser type heat gun to measure if one cat is hotter than the other.

Bigger engines are louder, I have the stock 4.8L exhaust on my 408 engine and its is distinctively louder.