Ford XLT 3.5 L Ecoboost engine 4X4 with a 6.5 ft bed towing a Keystone Cougar 5th wheel trailer 33 ft long. Trailer weighs 9,100 lbs, and the truck weighs 5,700 lbs. The rear wake are is 65 sq ft. A project boat tail could reduce the wake area to 37 sq ft. A preliminary mpg scan gauge reading was 8.3 mpg Hwy. A projected wake area reduction of 44% yields a 22% improvement in Hwy mpg to 10.1 mpg. This is what this project is about.