Baldwin BT344-S vs FRAM HP4: Oil Filter Compatibility
Compare Baldwin BT344-S and FRAM HP4 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 13/16-16 thread.
Quick verdict
Both use a 13/16-16 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.
Baldwin BT344-S and FRAM HP4 specifications
How matching is scored| Specification | Baldwin BT344-S | FRAM HP4 |
|---|---|---|
| Thread size | 13/16-16 | 13/16-16 |
| Gasket OD | 71.4 mm | 71 mm |
| Gasket ID | 62.7 mm | 62 mm |
| Can OD | 94.5 mm | 95 mm |
| Height | 113.5 mm | 111 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 20 | 22 |
| Anti-drainback valve | No | Yes |
What matters in this specific comparison
Thread size matches: both are 13/16-16.
Gasket OD differs by 0.4 mm (Baldwin BT344-S: 71.4 mm, FRAM HP4: 71 mm).
Gasket ID differs by 0.7 mm (Baldwin BT344-S: 62.7 mm, FRAM HP4: 62 mm).
Baldwin BT344-S is 2.5 mm taller (Baldwin BT344-S: 113.5 mm, FRAM HP4: 111 mm) -- check clearance before substituting.
Can OD differs by 0.5 mm (Baldwin BT344-S: 94.5 mm, FRAM HP4: 95 mm).
Both open their bypass valve in a comparable range: Baldwin BT344-S at 20-20 psi, FRAM HP4 at 22-22 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.