Oil weight for 2000 Civic EX

The best suggestion is the one the manufacturer printed on the oil cap. The manufacturer’s tech writers, working from the design package, elaborated in the owner’s manual.

It would be foolhearty of me to suggest that I know more than the guys that designed and tested the thing. They did accelerated life testing, environmental testing, and countless other endurance and wear tests and analysis. Hey what’s the plural of analysis anyway? Analysises?