[ddaru_chee]

Is mixing oil a good idea? Cuz logically sometimes the chemical additive of each oil are different and may react harmful if they are mixed together. A solution is to use a semi synthetic oil rather than mixing. I use Total Oil Semi-Synthetic (Like Mobil One. also recomended by the dealer) SAE 10W-40. My Aveo never experience any problems, and it runs smooth to the next oil change.

But yes, I believe that full synthetic are better (but more expensive), so why pay more if you have almost the same quality?

But note this, don't be lazy to change your oil filters, cuz your its durability is not as good as the oil itself, you know...