FRAM PH4731 vs MAHLE OC 581: Oil Filter Compatibility
Compare FRAM PH4731 and MAHLE OC 581 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
Closest known dimensional difference: height -20 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.
FRAM PH4731 and MAHLE OC 581 specifications
How matching is scored| Specification | FRAM PH4731 | MAHLE OC 581 |
|---|---|---|
| Thread size | M20X1,5 | M20x1.5 |
| Gasket OD | 72 mm | 71 mm |
| Gasket ID | 62 mm | 62.5 mm |
| Can OD | 76 mm | 80 mm |
| Height | 120 mm | 100 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 12 | 14 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are M20x1.5.
Gasket OD differs by 1 mm (FRAM PH4731: 72 mm, MAHLE OC 581: 71 mm).
Gasket ID differs by 0.5 mm (FRAM PH4731: 62 mm, MAHLE OC 581: 62.5 mm).
FRAM PH4731 is 20 mm taller (FRAM PH4731: 120 mm, MAHLE OC 581: 100 mm) -- check clearance before substituting.
Can OD differs by 4 mm (FRAM PH4731: 76 mm, MAHLE OC 581: 80 mm).
Both open their bypass valve in a comparable range: FRAM PH4731 at 12-12 psi, MAHLE OC 581 at 14-14 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.