do what the manufacture say..
in hard driving, most manufactures recomend changing oil after 5000 km (hard driving is driving in cities)...
in soft driving , it is 10000 km. (soft driving is long routes)..
but keep in mind that use good quality oil.... caz the molecules of oil break down in an engine... and a good quality can only protect yr engine and serve these long terms...
synthetic is the best ... but its expensive...
and i dont know how long it can serve the engine...levin knows it... caz he uses synthetic
so levin... hwat do you say...