Baldwin B166 vs WIX 51661: Oil Filter Compatibility
Compare Baldwin B166 and WIX 51661 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 +3.8 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.
Baldwin B166 and WIX 51661 specifications
How matching is scored| Specification | Baldwin B166 | WIX 51661 |
|---|---|---|
| Thread size | M20x1.5 | M20x1.5 |
| Gasket OD | 64 mm | 63 mm |
| Gasket ID | 54.1 mm | 55.1 mm |
| Can OD | 96 mm | 68.3 mm |
| Height | 82.6 mm | 86.4 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 20 | 13 - 19 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are M20x1.5.
Gasket OD differs by 1 mm (Baldwin B166: 64 mm, WIX 51661: 63 mm).
Gasket ID differs by 1 mm (Baldwin B166: 54.1 mm, WIX 51661: 55.1 mm).
WIX 51661 is 3.8 mm taller (Baldwin B166: 82.6 mm, WIX 51661: 86.4 mm) -- check clearance before substituting.
Can OD differs by 27.7 mm (Baldwin B166: 96 mm, WIX 51661: 68.3 mm).
Both open their bypass valve in a comparable range: Baldwin B166 at 20-20 psi, WIX 51661 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.