Sir its all about brand & quality you use, i dont trust local qualities, same case happened with my lancer 1.5, Mitsubishi Motors used KIXX 10W-30 it gets blackish brown after 2000Km, when i started using Liqui Moly Super 10W-40, & it ran 5000 Km amazingly, I am using Liqui Moly Products for 3 Good years, so thats why am giving you advice accordingly.
10W-40 is all rounder
Liqui Moly Super LeichtLauf 10W-40 is Synthetic technology
Liqui Moly MOS2 10W-40 is semi synthetic
Remember fully synthetic oil does not last longer, due to its thinner viscosity, engine consumes oil.... after 3000 Km you have to top up 400-500 ml oil
Also dont ever use Engine Flush, it is never recommended or you can say i dont recommend
Use Liqui Moly 10W-40 and you will get the idea whether it is thinner or thicker