What kind of an improvement would i expect (if any) in MPG on a 99 dakota with a 5.2 if i put in a CAI and did some exhaust work? And i know its been asked before most likely but search never seems to work for me, what is the stock MPG rating of these trucks?

EDIT: 99 dakota 5.2L V8 4 speed auto 4x4 completely stock (i believe)

 

when I got my truck and it was stock, I was getting around 18-19mpg. intake, exhaust and superchips got me up to 20-21mpg. lift and bigger tires took me down to 17-18mpg.

 

i have no intention of a lift or bigger tires. i cant really afford either of them