Just purchased a used 2006 Z71 Silverado Here are some specifications:

Crew cab
Hard Tonneau Cover
Dual Exhaust
K&N Intake Filter Kit
LT Series (Leather, Bose speakers, etc)

My question is what kinda fuel mileage can I expect with the modifications that are on her now?

How can I find if there is already a chip installed? If not, would it be worth the money to install one?

Just purchased her yesterday so I don't know much of anything besides how to install a front license plate...lol

 

Welcome to the forum and congrats on the new purchase...
Your MPG will depend on what size engine you have, mosts mods are to improve performance not MPG...adding a chip may give you some improvement if you run it in economy mode but the cost to pay off ratio is not likely to happen... GM pretty much wrenched all the MPG they can out of a V8
if you have the 5.3 liter you will likely see 12-15 city and 18-20 highway, its all about your driving habits

 

Thanks,

Sorry yes I do have the 5.3L V8 engine. Thanks for the response. Looking forward to seeing what she can do. Hope you had a great memorial day.