MAHLE OC 47 vs Baldwin B178: Oil Filter Compatibility
Compare MAHLE OC 47 and Baldwin B178 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 3/4-16 thread.
Quick verdict
Closest known dimensional difference: height +10.7 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 47 and Baldwin B178 specifications
How matching is scored| Specification | MAHLE OC 47 | Baldwin B178 |
|---|---|---|
| Thread size | 3/4-16 | 3/4-16 |
| Gasket OD | 72 mm | 69.9 mm |
| Gasket ID | 62 mm | 60.9 mm |
| Can OD | 76 mm | 76.2 mm |
| Height | 119.5 mm | 130.2 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 32 | 30 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are 3/4-16.
Gasket OD differs by 2.1 mm (MAHLE OC 47: 72 mm, Baldwin B178: 69.9 mm).
Gasket ID differs by 1.1 mm (MAHLE OC 47: 62 mm, Baldwin B178: 60.9 mm).
Baldwin B178 is 10.7 mm taller (MAHLE OC 47: 119.5 mm, Baldwin B178: 130.2 mm) -- check clearance before substituting.
Can OD differs by 0.2 mm (MAHLE OC 47: 76 mm, Baldwin B178: 76.2 mm).
Both open their bypass valve in a comparable range: MAHLE OC 47 at 32-32 psi, Baldwin B178 at 30-30 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.