Since there are a lot of posts about Kirkland Motor oil, I found this post on PQIA's website for test and review of Kirkland Signature Full Synthetic SAE 5W-30 Motor Oil.
https://pqia.org/kirkland-signature-full-synthetic-sae-5w-30-motor-oil/
https://pqia.org/kirkland-signature-full-synthetic-sae-5w-30-motor-oil/