I have a 1998 Mitsubishi lancer with engine that started to consume oil with 20w50 oil with added oil treatment, i started doing this mix for my engine oil, 4 liters mixed with 120ml liqui moly oil additive " mos2 " and 1 can of mannol motor doctor 9990 but one of my friends told me i am overdoing it with the mos2 as the engine is a goner anyways and i am just getting any life out of it before changing the short block, so my question is should i use oil with mannol doctor only or keep using the mix i did?