MAHLE OC 978 vs FRAM PH3593A: Oil Filter Compatibility

Compare MAHLE OC 978 and FRAM PH3593A oil filters by compatibility, dimensions, thread size, gasket fit, bypass valve, anti-drainback valve status, and match confidence. Use this comparison as a fitment review, not as an automatic substitution guarantee. Both use a M20x1.5 thread.

Quick verdict

COMPATIBLEMatch score: 87

Closest known dimensional difference: height +2.3 mm. Verify application-specific requirements before substituting.

  • Thread size is the first hard-fit check for any comparison of spin-on filters.
  • Gasket OD and gasket ID are the most important seal-related dimensions.
  • Height differences can matter for clearance even when thread and gasket fit appear close.
  • Bypass and anti-drainback differences may be important, depending on the application.

MAHLE OC 978 and FRAM PH3593A specifications

How matching is scored
Specification
MAHLE OC 978
FRAM PH3593A
Thread sizeM20x1.5M20X1,5
Gasket OD70.8 mm71.1 mm
Gasket ID62.3 mm62.5 mm
Can OD75 mm84.07 mm
Height79.5 mm81.79 mm
Internal bypass valveYesYes
Bypass PSID1412
Anti-drainback valveYesYes

What matters in this specific comparison

Thread size matches: both are M20x1.5.

Gasket OD differs by 0.3 mm (MAHLE OC 978: 70.8 mm, FRAM PH3593A: 71.1 mm).

Gasket ID differs by 0.2 mm (MAHLE OC 978: 62.3 mm, FRAM PH3593A: 62.5 mm).

FRAM PH3593A is 2.3 mm taller (MAHLE OC 978: 79.5 mm, FRAM PH3593A: 81.79 mm) -- check clearance before substituting.

Can OD differs by 9.1 mm (MAHLE OC 978: 75 mm, FRAM PH3593A: 84.07 mm).

Both open their bypass valve in a comparable range: MAHLE OC 978 at 14-14 psi, FRAM PH3593A at 12-12 psi -- these ranges do not overlap.

Open related filters

Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.

OC 978 vs PH3593A Oil Filter Comparison | Filter-Match