You can find the chip tuning file for your Mercury Grand Marquis 2003 - 2012 4.6 V8 239hp vehicle on our site. These files are created especially for you and handed to you. All our Tuning files are extensively tested on Dynometer. The development of the tuning file for your Mercury Grand Marquis 2003 - 2012 4.6 V8 239hp vehicle is the result of a special product by EcuPrime Engineers. In addition, we can increase the power of your vehicle from 239 HP to 260 HP, 382 Torque to 400 Torque.