Originally Posted by Zeeper
No, if the service department has trouble doing oil changes what makes you think they have mastered how to mess with your car to affect MPG's without throwing codes.
PS what transmission do you have and what kind of driving do you do, those make a big difference in expected MPG's
I have an automatic (I did this to save mileage but I really wanted manual) and as far as driving, I am for the most part conservative in that I don't floor it from start, etc. My daily drive is 130 round trip, mostly highway.