Recommended oil for Prius is 0/20 for the best mileage and best output. Don't feed higher viscose oils like 10/40, 15/40, 20/50, etc.
Presently only Kixx has 0/20 4L tin pack price 2800 and SCI is upto 6K.
If cannot find 0/20, then 0/30 by Kixx Pao1, LM, ZIC ow, etc.
Also read a separate thread "very bad choice of oil for prius" if have time.