Brother I would suggest to start from 5w-30 (if engine is perfectly healthy), then move to 10w-30 or 5w-40, and lastly, 10w-40.
Prefer fully synthetic, from some reputed brand, meeting latest API SN /SN Plus, and / or ILSAC GF-5 criteria. Of course, oil should be 100% genuine and original.
5w-30: Total Quartz 9000 Future Series.
5w-40: Caltex Chevron, Shell, ZIC.
10w-40: ZIC.
Change oil + genuine oil filter after every 5,000 Kms or 06 months (whichever comes first). Do not drag them beyond these limits.
Do engine flush before switching to new oil brand and grade; provided engine seals are perfectly healthy.
I hope, it helps. Thank you.
