Additives to me are like all the different types of specialty oils you see advertised.. If you are going to run the mileage way over then they MAY be worth the extra cash but otherwise they are just a waste of money if you do the regular maintenance at the intervals prescribed by the MOCO...... I fell into that trap before but soon realized what a load it was.. When ANY manufacturer claims anything, they are running all tests under ideal conditions to maximize the results in their favor.. I use the regular HD 20-50 in the engine and formula plus in the trans and primary. Because I do the maint at the prescribed intervals the drain plugs have had no debris clinging to them and the money I save can be spent on more useful things like...CHROME :bigsmiley12:.. I know I will probably get flamed for this but it is my opinion..