I used Kixx 5w-30 in my Vitz 2005 twice. Very good results, 6K-7K run. Though they are rated for 8K but just be on safe side.
Now a days I have Liqui Moly 5w-30 in my car which I wanted to try. I can't say it's better because it's costly or made in Germany. But I found KIXX to have better performance in 1KR-FE Engine and lower noise.
Fully Synthetic oils with latest specs are good for 0W-20 as they don't change molecule structure too much with temperature.
These cars need qualified technicians who actually know what they are doing. Blindly following what their ustad did 20 years ago doesn't work and makes car perform worse. So it's always a good idea to buy your own oil from a reputable reseller, go to workshop who has experience with OBD values and Calibrations. Just disconnecting Battery to reset ECU is not enough and not a good idea also as ECU learns values over time.