I forgot about 2 cases of amsoil 10w-30 which I recently found in my basement. I suspect they must be about 10 years old. From reading online, I think it’s safe to use in my low miles AP1. Or should I just dump it in my BRZ. Thoughts?

 

Sealed bottles of oil kept indoors will remain useable for life. Just shake the bottles before use as additives will settle to the bottom. That oil is perfect for your S2000. it might not meet the current specs for the BRZ but I doubt it would harm anything. Perfect for the S2000.