I've got close to 400K on my 99 dodge diesel and have never used any kind of additives, in my opinion they're snake oil. Someone will be along shortly however to tell you that your truck will die within the first 50 miles without XYZ Super Miracle Additive.
a 99 Dodge is not the same type of critter as one of these new emission choked common rail motors
the fuel and injection systems are completely different
I buy premium diesel when I can get it , otherwise add Howes or Stanadyne
Optilube is very good , but its not on the shelve in these parts
