2006 silverado 4.8 gas mileage and performance.

[deadman]

im looking to better my 4.8 completely stock engine truck. i would most importantly like to get better gas mileage. if i could get a few more horses out of this truck as well as better gas mileage i would be super happy. i keep the tires filled with air and keep the oil changed regularly and dont haul anything. i would think a k&n filter would help or a programer. problem is i know almost nothing about these trucks other than at 175000 mile it runs great other than the check engine light comes on every few days and i think its a bad gas cap or atleast that what the scanner i have keeps showing. any ideas on how to improve my truck?

[Chriscon7]

Heard nothing but good things about a custom tune. I plan on getting on sometime.
Increase in power and some gains in fuel economy

[88m53453]

im looking to better my 4.8 completely stock engine truck. i would most importantly like to get better gas mileage. if i could get a few more horses out of this truck as well as better gas mileage i would be super happy. i keep the tires filled with air and keep the oil changed regularly and dont haul anything. i would think a k&n filter would help or a programer. problem is i know almost nothing about these trucks other than at 175000 mile it runs great other than the check engine light comes on every few days and i think its a bad gas cap or atleast that what the scanner i have keeps showing. any ideas on how to improve my truck?

My 05 Sierra with 178k on it gets 20-25 . I have a Black Bear Tune and for what it is, it feels pretty quick, Not as fast as our 03 Tahoe with a 5.3 and a Wait For Me Tune, but good nonetheless

[Chriscon7]

My 05 Sierra with 178k on it gets 20-25 . I have a Black Bear Tune and for what it is, it feels pretty quick, Not as fast as our 03 Tahoe with a 5.3 and a Wait For Me Tune, but good nonetheless

20-25? Waaaaah??
I filled up yesterday and was stoked to have gotten 19 mpg, cause im usually at 16ish..
You drive all highway or what?