Kirkland (Costco) synthetic oil review: who makes it and is it good?
Yes, Kirkland full synthetic is a good oil for most gas cars. The 0W-20 and 5W-30 carry API SP, ILSAC GF-6A and GM dexos1 Gen 3, and lab tests put it level with Mobil 1 on the basics. Highline Warren supplies it. Skip it if your manual calls for a European or other carmaker approval that isn't on the jug.