If you got the cruze for MPG's and drive as such. A tune may decrease your MPG's. Many, including myself, have reported that a tune wakes the car up and thus is more fun to drive. I detuned our car after one update I didn't like and the next morning my wife said "WTF did you do the to car!?! It's feels like a paperweight!!! Change it back NOWWWW!!!" So I changed it back. If your looking for some type of performance kick, a tune is the answer.