Bro,
It is written in the user manual. You have to search for it. But it is definitely there. Use 5W-30 as mentioned on the back of the book. Internationally they put 0w-20 as well. But its not suitable for our climate (this is debate able
) . Some people use 0w-20 as it is written in the same manual. However, it clearly states the temperature / weather conditions it (0w-20) must be used in.
Pak suzuki sells us semi-synthetic engine oil at higher then market prices. They will tell you . "If you do not get an oil change from us, your warranty will be void". If you ever take a complaint to them , the first thing they will check is , "did you get the routine maintenance done from them or not". So....you have a choice. Get average quality engine oil from them and keep your warranty intact. OR get a genuine, branded, fully synthetic 5w-30 (or 0w-20) from a trustworthy dealer. Aimsoil , Liqui Moly or any other brand that you feel comfortable with and get long lasting power and fuel efficiency from your engine.
I personally use Aimsoil 5W-30 in my CIAZ. Yes it costs a lot more then others , but I have noticed a significant reduction in engine noise ever since I started using it. Feels smoother as well.