Bro Daihatsu Mira doesn't require 20w-50 oil in it, as per OEM recommendations. It's too thick.
0w-20 or max. 5w-30 is the recommended oil grade for these used JDM cars (660, 1000 cc, etc.)
I would suggest you to use 5w-30, API SN / SN Plus, Fully Synthetic Engine oil from some reputed brand. And if you want best for bucks, use Total Quartz 9000 Future series along with genuine oil filter. Change both after every 5,000 Kms, and ensure that oil is 100% original & genuine.
