Question: what is the difference between a pf63 vs pf63e oil filter?
Answer: What is the difference between a pf63. ... The older PF63 has a by-pass pressure of 12 PSI. The newer ecore PF63E has a bypass pressure of 22 PSI. If your application calls for the 63E and runs at a higher oil pressure, it's possible the classic 63 might run with the bypass open, allowing unfiltered oil through.