diesel oil additives is useless if you are using group IV and group V base stock synthetic. Synthetic oil like amsoil, royal purple, red line, motul, etc. are using group IV and group V base oil synthetic and manufacturers already blended them with 20 or more chemical additives package to do their job. unless you are using mineral oil base stock like conventional oil then u may need this additives like pertua, etc...in your oil.....but again if you are using group iv & v synthetic oil then it is no need of these additives because group iv & v synthetic oil has superior additives and well researched and tested in extreme conditions like racing circuits......