FRAM PH49A vs WIX 57791: Oil Filter Compatibility
Compare FRAM PH49A and WIX 57791 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 11/8-16 thread.
Quick verdict
Both use a 11/8-16 thread.
- 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 PH49A and WIX 57791 specifications
How matching is scored| Specification | FRAM PH49A | WIX 57791 |
|---|---|---|
| Thread size | 1"1/8-16 | 11/8-16 |
| Gasket OD | 102 mm | 100.8 mm |
| Gasket ID | 92 mm | 91.11 mm |
| Can OD | 107.7 mm | 110 mm |
| Height | 263.91 mm | 263.7 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 12 | 13 - 19 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are 11/8-16.
Gasket OD differs by 1.2 mm (FRAM PH49A: 102 mm, WIX 57791: 100.8 mm).
Gasket ID differs by 0.9 mm (FRAM PH49A: 92 mm, WIX 57791: 91.11 mm).
FRAM PH49A is 0.2 mm taller (FRAM PH49A: 263.91 mm, WIX 57791: 263.7 mm) -- check clearance before substituting.
Can OD differs by 2.3 mm (FRAM PH49A: 107.7 mm, WIX 57791: 110 mm).
Both open their bypass valve in a comparable range: FRAM PH49A at 12-12 psi, WIX 57791 at 13-19 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.