comments

I am late to the party, but for anyone else who sees Kirkland motor oil and googles it than lands on this page. Consumer Reports doesn't rank motor oil. 10+ years ago Consumer Reports said the brand doesn't matter as long as it meets the requirements laid out in the owners manual.

Consumer Reports: https://apnews.com/afd94f38faf468f8c32c30a44589f62c

Oil Testing Lab looked at this again and concluded still true: https://www.thedrive.com/the-hammer/12762/10000-sample-study-on-motor-oil-supports-what-consumer-reports-concluded-a-decade-ago

The only thing I found Consumer Reports weighted in on is non-synthetic vs synthetic. https://www.consumerreports.org/car-maintenance/should-you-use-synthetic-oil-in-your-car/

As noted in other comments this oil is produced by Warren Distribution Inc. If you look closely at the packaging it says manufactured by Warren. They produce lots of oil for store brands. I believe some popular ones are Walmart and AmazonBasics. http://www.warrendistribution.com