ACDelco PF26 vs Donaldson P550965: Oil Filter Compatibility
Compare ACDelco PF26 and Donaldson P550965 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 M22x1.5 thread.
Quick verdict
Bypass presence unknown on one or both filters
- 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.
ACDelco PF26 and Donaldson P550965 specifications
How matching is scored| Specification | ACDelco PF26 | Donaldson P550965 |
|---|---|---|
| Thread size | M22x1.5 | M22x1.5 |
| Gasket OD | 70.8 mm | 71 mm |
| Gasket ID | 61.5 mm | 61 mm |
| Can OD | 94.1 mm | 93 mm |
| Height | 158.75 mm | 91 mm |
| Internal bypass valve | Unknown | Yes |
| Bypass PSID | Unknown | 12 - 17 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are M22x1.5.
Gasket OD differs by 0.2 mm (ACDelco PF26: 70.8 mm, Donaldson P550965: 71 mm).
Gasket ID differs by 0.5 mm (ACDelco PF26: 61.5 mm, Donaldson P550965: 61 mm).
ACDelco PF26 is 67.7 mm taller (ACDelco PF26: 158.75 mm, Donaldson P550965: 91 mm) -- check clearance before substituting.
Can OD differs by 1.1 mm (ACDelco PF26: 94.1 mm, Donaldson P550965: 93 mm).
Open related filters
Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.