A whole bottle in a half tank seemed a little excessive but alright.... I bought my gallon of DFC from
www.autoil.com seemed like a pretty decent deal. I heard of the 85 but normally use DFC just because it supposedly helps with smoke as well as the long list of other stuff it does.
Cetane and mileage isn't a direct relation, cetane is the spontaninty of the combustion occuring. Perhaps PS creates a mileage boost but it isn't because of cetane.
