I always buy from Tesco and sometimes Giant.

I only aim for Fully Synthetic ones.

Mostly they sell ( on offer/promotion):

1. Castrol Edge 5w-40 4Litre - Mostly RM149
2. Shell Helix Ultra 5w-40 4Litre- Mostly RM149 sometimes even lower RM129
3. Mobil 1 New Life 0w-40 4Litre- Mostly RM149 but very rare got offer this one
4. Mobil Super 3000 5w-40 5Litre- Recently got offer I bought for RM129 I think .

Got 1 more always offer but I don't buy :

Mobil 1 Peak Life 5w-50 4Litre- Mostly RM 149 but I cannot use because 50 weight engine oil is not meant for normal passenger cars. Too heavy.

This post has been edited by k!nex: Sep 26 2015, 08:40 PM

THis exact thing I bought from our forumer "gagak" for around RM150~ only. Good oil though.
For myself, I will see which one on offer then buy which one. However, if Castrol , Mobil and Shell on offer, then my first choice to last choice for full synthetic is:

1. Castrol Edge 5w-40
2. Mobil New Life 0w-40
3. Shell Helix Ultra 5w-40
4. Mobil Super 3000 5w-40

In terms of durability, I found Castrol Edge oil is more durable .