WIX 51800 vs FRAM PH49A: Oil Filter Compatibility
Compare WIX 51800 and FRAM PH49A 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
Large bypass PSI mismatch: 18 psi
- 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.
WIX 51800 and FRAM PH49A specifications
How matching is scored| Specification | WIX 51800 | FRAM PH49A |
|---|---|---|
| Thread size | 11/8-16 | 1"1/8-16 |
| Gasket OD | 100.8 mm | 102 mm |
| Gasket ID | 91.11 mm | 92 mm |
| Can OD | 108.5 mm | 107.7 mm |
| Height | 263.27 mm | 263.91 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 30 | 12 |
| 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 (WIX 51800: 100.8 mm, FRAM PH49A: 102 mm).
Gasket ID differs by 0.9 mm (WIX 51800: 91.11 mm, FRAM PH49A: 92 mm).
FRAM PH49A is 0.6 mm taller (WIX 51800: 263.27 mm, FRAM PH49A: 263.91 mm) -- check clearance before substituting.
Can OD differs by 0.8 mm (WIX 51800: 108.5 mm, FRAM PH49A: 107.7 mm).
Both open their bypass valve in a comparable range: WIX 51800 at 30-30 psi, FRAM PH49A 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.