Originally Posted By: EricF
the FL-1A is made by Purolator and is a Purolator Pure One filter in a regular white can Purolator casing.
Not the whole story, as clarified by sayjac here:
Originally Posted By: sayjac
Can't add much to what's been said. Great value Purolator made with base end bypass as per FoMoCo specs.
More specific info here. And, here.
Motorcraft locates the bypass valve in the end cap, while the Purolator equivalent does not. Because of this, the Motorcraft filter will not "bypass" oil across the dirty side of the filter element while the Purolator will.
Purolator builds the Motorcraft filters, but it's to Ford's specs. The Motorcraft version is superior.