do not touch anything, write all settings down.

most chevy truck owners myself included are not getting thay mpg.

good luck,

 

stock 2007 extended cab Z71 with Motor Management system. computer reads 18.3 overall, but have gotten almost 20mpg when checking myself!!!

 

I also have an '07 5.3 with Active Fuel Management Crewcab. I get around 21 highway and about 18 on short trips with some city diriving.

 

no offense but i call BS on these lasst 2 posts.

 

I have an '07 NBS ext cab 5.3w/ AFM. DIC reads an average of 17 mpg. Most of my driving is about 60 mph on the highway and the computer reads out 24mpg while in V4 mode. Around town in V8 mode im getting about 17 mpg. I've kept track in a log manually ever since I got the truck and im getting between 17 to 20 mpg on my own calculations. The more you drive with cruise controll with the AFM, the better your mileage is going to be. As much as you dont want to believe it cdusthockey, the new trucks are getting this kind of mileage.

 

I have a 2007 silverado 1500 LTZ NBS with the 5.3 and am getting 15.9 MPG right now. I drive more back roads than highway. That's also with a tonneau cover, royal purple oil and a GM cold air intake, all of which are rumored to increase MPG. I have to drive in 4WD on occasion and have noticed a dramatic drop in MPG when doing so.

 

Tonneau actually reduces mileage Tatonka... had one on my 04, and it dropped my about 0.5 mpg ave, it also rubbed the sh-- out of my bulkhead without me knowing.

Right now I'm running 2007 Std cab/Bed 5.3 with AFM get 16-16.5 average (mostly city and rush hour stop and go.) On a 300 mile trip I took when I first got it, using cruise control 90% of the time staying around 70-75 mph I calculated 22-23 mpg.0 mods.

 

My daily driver is a 06 Z71 ext. cab with the 5.3 and the engine mgmt system. When it was new I averaged 16.7 now with almost 60,000. miles I get 17.3
I installed a Flowmaster cat back the week I bought it and also a Tru-Flow intake.