There are several ways to improve Fuel Mileage on a Ford PowerStroke 6.4L. One of these is by performing a regular maintenance on your 6.4L Power Stroke diesel to permit your vehicle to perform more effective. Replacing its air intake and air filter with a specially designed for high performance Volant Diesel Cold Air Intake. This will allow a greater flow of cold air to your engine. Volant Filters are also intended to permit an upgraded air flow at the same time dirt free air for more efficient result. This CAI Kit draws air from the stock side emit grill. Volant’s system increases the HP up to 23 additional hp and boosts mileage for almost 2 miles per gallon.