Edge Products Mileage Max, fits the 03-07 6.0L Ford Powerstroke. YOU GET IMPROVED HORSEPOWER AND FUEL ECONOMY IN ONE SIMPLE-TO-INSTALL PRODUCT!! TESTED TO DELIVER GAINS OF UP TO 7% IN FUEL EFFICIENCY AND 35HP IN PERFORMANCE!! Whether you use your truck as your daily driver or your cross-country hauler, the Mileage Max delivers something every driver wants: Improved Fuel Economy!! In less than 10 minutes you can install this money saving in-line module that not only delivers proven fuel economy gains of up to 7%, but also delivers a boost in Horsepower. Simply put, "The more you drive, the more you save!!" Developed and tested using innovative engineering techniques, the Mileage Max takes a bite out of rising fuel prices by optimizing the timing and pressure of fuel delivery, which has been proven to improve not only fuel economy, but also horsepower.