I use Motorcraft Cetane Boost in Summer months and Motorcraft Anti-Gel in the Winter months. I work for a WD and get it pretty cheap. They are recommended by Ford to improve lubricity, this was a big issue with the HEUI systems used in the 7.3 and 6.0 Ford diesels. Have always used the products in every diesel I have owned but have not monitored or felt any MPG or performance increase. More of a preventative measure for me. I recommend always using some type of anti-gel during the winter months. The risk of being stranded somewhere in the cold or sustaining fuel system damage is too great for me to save a few bucks on anti-gel IMO. I am getting too old for that s**t.
