As a former Toyota/Mazda
As a former Toyota/Mazda dealer tech. And subsequently a shop owner. I retired 25 years ago . I own 2 Prius. 08 an 2011. Change oil every 5k. Mostly at dealer. They are reasonable. My gen3 gets 0W20. I used that in my gen 2 from 30k to 120k then was advised to use 5w30. Gen 2 has 200k . love my prius...