My 1999 Integra uses Synthetic Oil - should I never go back to regular oil?
Your Integra could not care less…
Use synthetic or conventional, either way you won’t hurt your car.
Check the owner manual. You can use the minimum stated there, or better.
Mix or match.
You can switch back and forth with no problems.
In the first year or two of synthetic oils there were several problems with switching back and forth. That has all ended. Now you hear of an occasional issue blamed on it, but in reality not.
Convert to super-tech synthetic from Wal-Mart, it is much cheaper. Change or mix at will, it won’t hurt.