Answer
The oil filter is among the highest-leverage engine-maintenance choices: a poor filter passes contaminants, starves oil at startup, or fails to seal. Specify by filtration efficiency, bypass-valve setting, anti-drainback valve, and exact fitment. HW Filter builds oil filters in spin-on and cartridge formats with documented efficiency and pressure ratings for passenger, commercial, and private-label programs.
Last updated: October 13, 2026
How to Read Oil Filter Part Numbers: Decode OEM & Interchange Codes
An oil filter part number looks like random letters and digits — but it carries real information if you know the structure. For importers, catalog managers and mechanics, decoding these numbers prevents wrong shipments and speeds up cross-referencing. This guide breaks down the common formats and the attributes each number implies.
Why Part Numbers Confuse Buyers
Every carmaker and aftermarket brand uses its own numbering logic. The same physical spin-on filter can carry a Toyota 90915-10001, a Mann W 67/1, and your private-label HW-OF-104. None of these “mean” the same thing across brands — only the physical attributes prove they are interchangeable.
Anatomy of a Typical Spin-On Number
| Segment | Example (Mann W 67/1) | What it implies |
|---|---|---|
| Prefix / family | W | Spin-on series |
| Base number | 67 | Size family (gasket, thread group) |
| Suffix | /1 | Variant (height, valve, media) |
OEM numbers are less systematic — they often encode model year or platform. Treat them as keys to a catalog, not as dimensions.
The Attributes That Actually Matter
When cross-referencing, ignore the number’s “meaning” and measure these:
- Thread: e.g. M20×1.5, 3/4″-16 (confirms it screws on).
- Gasket OD & ID: confirms the seal seats.
- Height: confirms housing clearance.
- Bypass valve pressure: must match or exceed OE.
- Anti-drainback valve: required for many engines.
Our oil filter range publishes these attributes per SKU so buyers can verify a match before ordering. The oil filter cross-reference guide shows the full attribute table in practice.
Practical Decoding Workflow
- Take the customer’s OE or box number.
- Look it up in your cross-reference to find the physical attributes.
- Match those attributes to your SKU — not the number string.
- Ship only after the attributes are confirmed equal.
Frequently Asked Questions
Can two different numbers be the same filter?
Yes, very often. Different brands and OEMs assign different numbers to one physical filter. The only reliable check is matching thread, gasket, height and valve specs.
What happens if the bypass valve differs?
A bypass valve that opens too early lets unfiltered oil circulate; one that never opens can starve the engine at cold start. Always match the OE bypass pressure.
Do cartridge and spin-on share numbers?
No — they are physically different formats and use separate numbering. Never assume a cartridge cross applies to a spin-on of the same “family.”