fuel for my mileage
 

my 2007 avalanche gets poor fuel mileage. what can I do to improve it ?

Chevy Avalaches are NOT renowned for their fuel economy.
What kind of mileage is your avalache getting right now?

You can try getting a cold air intake system to increase your mpg? But if you're on a budget, you can try things like using a tonneau cover for your bed to decrease the drag, also reduce your load (do you store unnecessary stuff in your truck?), and check the air pressure on your tires regularly (low pressure causes your engine to work harder). Just a few tips, hope it helps. :)

What he said is right
 

Besides tonneau covers to minimize the drag, you can lessen your use of your car's air-con (only use it when necessary) and ease up on the gas pedal.

the avalanche box comes from factory with a hard tonneau.
please explain how adding a cai helps fuel mileage?

Getting a cold air intake system increases air available for your engine, it can help fuel efficiency which means it won't use up more fuel for your car to reach the same horsepower. I checked this link out for complete information, hope it helps.

if more air flows in, more fuel is metered to match it... how does that equate to fuel savings. the only thing that changes is the amount of throttle position opening.
the function of the 02 sensors; to maintain the best fuel ratio possible 14.7:1 for emissions. It will maintain this most of the time. That is why you would have more power....fuel savings...nope. X amount of fuel in = x amount of fuel metered.