Donaldson P550518 vs Mobil 1 (ExxonMobil / Mann+Hummel) M1-303A
Donaldson P550518 and Mobil 1 (ExxonMobil / Mann+Hummel) M1-303A are commonly compared by buyers looking for a close replacement. This page compares their published specifications so you can quickly see where they align, where they differ, and whether either filter looks like the better fit for your application.
Quick verdict
Large gasket OD variation · Large gasket ID variation
- 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.
Donaldson P550518 and Mobil 1 (ExxonMobil / Mann+Hummel) M1-303A specifications
| Specification | Donaldson P550518 | Mobil 1 (ExxonMobil / Mann+Hummel) M1-303A |
|---|---|---|
| Thread size | 13/16-16 | 13/16-16 |
| Gasket OD | 88 mm | 88 mm |
| Gasket ID | 79 mm | 79 mm |
| Can OD | 94 mm | 93.73 mm |
| Height | 136 mm | 136.65 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 12 - 15 | 12 - 15 |
| Anti-drainback valve | Yes | Yes |
| ID top | Unknown | Unknown |
| ID bottom | Unknown | Unknown |
What matters most in this comparison?
Thread match: A direct spin-on substitute starts with the same thread size. If the threads differ, the comparison stops there.
Gasket fit: Even when thread size matches, the gasket outside diameter and inside diameter still control whether the filter seals safely against the mounting surface.
Height difference: Small height differences may be acceptable, but longer filters can create clearance problems in tighter installations.
Valve behavior: Bypass and anti-drainback differences can matter in real-world service, especially on cold start or in applications sensitive to oil drain-back.
Related filter pages
Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.