No, in fact quite the opposite. Even on a performance tune, if you continue to drive the car in the same way as you did before the upgrade, your fuel consumption will probably improve. Of course if you have a track map installed on the car and you are driving the car under the conditions with which a track map is intended you’re likely to find a slightly reduced mpg figure. Economy tuning can have a dramatic effect on fuel consumption, with considerable improvements being achieved along with huge money savings on fuel.