Recently i started a thread about bad quality fuel and tried to find out its relations with Engine oil.
i got only 1 reply and that was from zulfiqar (a man with handsome/authentic knowledge)
and according to him, bad fuel quality DOES NOT bring any significant affect on quality of the engine oil. However always driving cold car is harmful. Am frankly still working on it and yet reaching different technicals to dig out more details.
i think all these points has a direct linked with "fuel quality" which am still working on to find as well.