Tbh I think OP hasn't driven a brand new car over 50,000 km yet. There's something making assumptions out of experience and out of reading pages on wikipedia and Google shoogle.
Just saw uncles car leave for Gujrat- 205,xxx on ODO. Been using 20w-50 from day one till today- Oil changed at 4,000-5,000km.
Nuff said. Oh, driver maintains it as well- usually driven once a month or whenever uncle comes to Pakistan.