Guys, Ceratec, motor protect etc. and any other additives are recommended to be used at the minimum level. Too much usage is not good for your engines especially seals. Further, fully synthetic oils are designed for engines manufactured under strict control of quality where even temperature matters during manufacturing/assembling (not local assembled engines). Also, do research and find out for yourself, if you are changing fully synthetic oil more frequently you are actually causing more damage to your engine. Fully synthetic oils (when poured in new) cause max wear and tear within the engine ... the wear & tear reduces as they get some miles on them. Regular oil filter change is also a must. People looking at the color of oil as a gauge to know the quality of oil are hugely mistaken ... that's not how you figure out the oil quality. Your mineral oil if changed within 3 mo or max 5000km is as good as a synthetic oil .... based on a study conducted on NY taxi cabs (mineral vs synthetic oil) .... Of course, synthetic result in reduced wear & tear overall and better fuel efficiency in the long run ... hope this helps ....