Reading OEM Filter Numbers: Reference Is Not Fitment

13 November 2026 · Filters

Most filter enquiries start with a number: 447300-2150, MB220900, CX0706. That number is a reference, not proof of fitment. The same reference can appear on parts with different threads, different media and different overall height.

Three kinds of number

Why a reference can be misleading

• One OEM number may have several supplier variants with different thread sizes.
• A reference number may cover a family of elements with different heights.
• Some numbers are printed on the housing, not on the element.
• Aftermarket numbering systems overlap between manufacturers.

How to confirm before ordering

1. Take the number from the part being replaced, not from a list.
2. Measure the key dimensions: thread, diameter, height, seal diameter.
3. State the vehicle or engine code.
4. Send a photo of the old part next to a ruler if the number is worn.

What we do with an OEM number

We will tell you what the number is listed as in our catalogue and which item we would supply. Where the cross-reference is not documented, we say so and ask for dimensions instead of guessing. We are not an authorised dealer of any OEM brand, and OEM numbers are quoted for cross-checking only.

Examples from the catalogue

Browse all filter categories · Send a number for cross-checking