5W30 is too thin IMO. use 40 oil better

Amsoil I dunno. Wait for the other members to respond. Whatever brand you choose, choose atlease a 40 oil. 30 too thin. And 50 too thick. And avoid Shell. Others should be OK

Either one will do fine. No prob. Fully better. Longer service interval and lighter on the engine with good protection.

Mobil should be better. The W is rating for winter. Malaysia no snow, don't worry

What ready stock?
U can avoid AMSoil in the future. .Not good for our car.. Im using it The Gold Signature series now..
In the future just stick to 0W/5W/10W-40 Fully synthetic oil.. Dont use 50 oil cos its too thick and 30 cos its too thin and ur engine is not designed to run oil that thin without properly design oil  cooling system.
THe Winter grade 0W/5W/10W u see in front is totally irrelevant to us.. We are in a tropical country where the ambient temp will never drop below 10degrees..
Good brands I would recommend Castrol, Havoline, Cusco, Eneos, Idemitsu.. Avoid Shell at all cost.. Even petronas oil are better than Shell..
The difference between Fully and and semi are the oil bases.. Fully synthetic are much more better at lubricating the engine and high speed/high temp stability.. And has better cleaning and acid neutralisation properties.. But its recommended to change semi sync at 5k and fully sync at 7k-8k if ur car is driven heavily or always gets stuck in jams..
U shd fix rear bumper rockets for ur car like in johnny english..

Mechanic.. His name Ah Chun

---

Added on February 13, 2012, 9:19 pm

Try castrol edge 5-40

Are you planning go back proton service center?

Hmm.. You can go to castrol authorized service center and buy..
Will cost you RM 185..
If you service there will cost RM 200 with oil filter and labour

Buy at Tesco. For sure original oil. Or you can go to any Castrol Auto shops. They only sell genuine oil there