As told by the guy at the shop and my car forum, using 20w is more then enough for since I dun go Malaysia. If go up to Malaysia, 30w will be better tho as the oil for 20w is thinner then 30w. I think 50w is better for cold weather country because of the thickness. That's what i know about tho.
I gotten 4 x bottle from him and TCM only use 3.5 bottle. I still got half bottle left for 20w. I will buy another 3 more bottle for my next servicing. Better to buy 7 at one go because Latio only drink 3.5 bottle.
Price is $15 each. I heard from the guy that Amsoil is selling very well, the top seller is Redline.
Mobil is good but Amsoil is cheaper and good too. Silent is great!

For cheong, I dunno leh.

I paid $110+ because of $20 charge for balancing and rotating of Front Tyre, so it's $90+ for sure.