Bosch 3421 vs Bosch 3422: Oil Filter Compatibility
Compare Bosch 3421 and Bosch 3422 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
Large bypass PSI mismatch: 16.5 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.
Bosch 3421 and Bosch 3422 specifications
How matching is scored| Specification | Bosch 3421 | Bosch 3422 |
|---|---|---|
| Thread size | 3/4-16 | 3/4-16 |
| Gasket OD | 70 mm | 70 mm |
| Gasket ID | 61 mm | 61 mm |
| Can OD | 75.01 mm | 75.01 mm |
| Height | 120.4 mm | 120.4 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 25 - 35 | 12 - 15 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are 3/4-16.
Gasket OD is identical at 70 mm.
Gasket ID is identical at 61 mm.
Height is identical at 120.4 mm.
Can OD is identical at 75.01 mm.
Both open their bypass valve in a comparable range: Bosch 3421 at 25-35 psi, Bosch 3422 at 12-15 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.