Originally Posted By: David1
From Pics I have seen many Mobil 1 Oil Filters ** Not ALL ** have the same bypass set up as FRAM... but many do and as you can see from pic its A leaf spring at the bottom of the oil can with the bypass built in with another spring.

here is a pic

perhaps it might be a better plastic then FRAM and Im not saying the FRAM bypass is bad...
Im just making a point.

The "plastic" (high temperature nylon composite) in both filter brands is specified for the high temperature oil environment they are designed for.

There has never been any reports of "plastic" bypass valves that look defective after a filter cut-open.