Premium Guard PG4612 vs Baldwin B421: Oil Filter Compatibility
Compare Premium Guard PG4612 and Baldwin B421 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
Both use a M20x1.5 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.
Premium Guard PG4612 and Baldwin B421 specifications
How matching is scored| Specification | Premium Guard PG4612 | Baldwin B421 |
|---|---|---|
| Thread size | M20x1.5 | M20x1.5 |
| Gasket OD | 62.74 mm | 64 mm |
| Gasket ID | 55.37 mm | 54.1 mm |
| Can OD | 65.53 mm | 76.2 mm |
| Height | 76.45 mm | 72.2 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 17 | 14 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are M20x1.5.
Gasket OD differs by 1.3 mm (Premium Guard PG4612: 62.74 mm, Baldwin B421: 64 mm).
Gasket ID differs by 1.3 mm (Premium Guard PG4612: 55.37 mm, Baldwin B421: 54.1 mm).
Premium Guard PG4612 is 4.2 mm taller (Premium Guard PG4612: 76.45 mm, Baldwin B421: 72.2 mm) -- check clearance before substituting.
Can OD differs by 10.7 mm (Premium Guard PG4612: 65.53 mm, Baldwin B421: 76.2 mm).
Both open their bypass valve in a comparable range: Premium Guard PG4612 at 17-17 psi, Baldwin B421 at 14-14 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.