[Coroner]

The IAT chip is really designed for performance and power. Power uses more fuel and will probably undue the work of the other mods. Some believe that increasing the performance of the motor will result in less work for the engine and result in better fuel mileage. Make sure you test that mod thoroughly and only after the other mods.

From what I understand, (And others may jump in here), the IAT changes the voltage reading sensed by the ECU with regard to the MAF sensor and will run the FA mixture rich. A rich FA mixture (Like when the car is not yet warmed up) will give you power, but at the expense of economy.

JMHO