Regarding engine oil for 1 KR-FE in Toyota Passo, I would like to share my experience:
I own Toyota Passo X, 2013 model, with ~50k odo reading as of now. Since day 01, I have been using API SN, 5w-30, Fully Synthetic engine oil, and engine has been working flawlessly.
First I have been using ENEOS Sustina (it's a bit expensive option) and now I am using Total Quartz 9000 Future series (Best value for money as per my experience).
With timely oil change along with genuine oil filter, air filter, etc. and routine maintenance; I have been getting 19.5 kmpl+ in winters, and 16.5 kmpl+ in summers (with AC) within city, but driven carefully with light foot.
The quantity I pour is 03 Liters; it touches the max. mark and stays there (even when I change engine oil after 5,000-6,000 Kms).