Motor Oil is basically 98% base oil (either synthetic or mineral or combination) plus 2% additives. Additive content vary from oil to oil. Over time depending on driving style, road conditions, etc. additive content dwindles, Manila driving is considered severe condition (stop and go, traffic, high pollution, etc.). If you buy a so-so oil, additives are very helpful. If you have the tendency to extend periodic maintenance like jeepneys, trucks, taxis, then it is important.