Fitment Completeness & Coverage

Editorial supplement (manual). This page documents the current granularity of the fitment data in the canonical dataset and the forward path to OE-number-level fitment. It complements the auto-generated vehicle-fitment.md (model ↔ vehicle-type mapping). It is not overwritten by scripts/build-db-pages.py.

What "fitment" means at this stage

Fitment in the hycarfilter dataset is expressed at two levels of granularity:

Level	Where it lives	Example	Status
Vehicle type	products[].applicable_vehicles[]	passenger cars, heavy trucks, agricultural machinery	✅ populated for all 22 SKUs
Fitment-critical detail	products[].dimensions{thread,gasket} and products[].materials{seal,endcap}	3/4-16 UNF, M16x1.5, NBR gasket	✅ populated where applicable (oil/fuel filters)
OE part-number level	products[].oe_numbers[] and products[].cross_reference[]	17801-XXXXX	⚠️ seed placeholders — unverified

The fitment table therefore tells a buyer which vehicle class a SKU serves, but not yet which specific make/model/year it fits. That second level is the destination for Phase 4+.

Fitment granularity by category

Category	Fitment-critical dimension	Current completeness
Air filter	Panel L×W×H, round H×OD×ID, seal	Dimensions present; vehicle-level fitment
Cabin filter	Panel L×W×H, frame & seal	Dimensions present; vehicle-level fitment
Oil filter	Thread, gasket, bypass setting	Thread + gasket present; thread is the OE anchor
Fuel filter	Thread / quick-connect, diesel vs gasoline	Thread + fitting type present; fitting is the OE anchor
Wiper blade	Length, adapter type	Length present; adapter set documented in editorial
Transmission filter	Transmission model (Aisin/ZF/GM), gasket material	Vehicle-level only — needs transmission-model key
LED lights	Socket (H4/H7), CANbus decoder	Socket present; decoder noted in editorial

Why transmission filters need the most work

Transmission filters are the least complete fitment dimension in the dataset. They are transmission-specific, not vehicle-generic — a filter matches a specific Aisin / ZF / GM transmission model and its pick-up tube, not a vehicle nameplate. The current applicable_vehicles value (automatic transmission vehicles) is too coarse to be a real fitment key.

Forward path: add a transmission_model / pickup_fit field to the schema, populate it per SKU, and regenerate the fitment index keyed by transmission model rather than vehicle class.

The OE-number roadmap

Reaching OE-part-number-level fitment is a data-verification exercise, not a writing exercise. It requires:

1. Confirming each SKU against manufacturer OE catalogues (per SKU, per market).
2. Replacing XXXXX / YYYYY placeholders with verified OE numbers.
3. Promoting status from seed → draft → final as each value is verified.
4. Regenerating oe-cross-reference.md from the verified dataset.

Until then, the OE and competitor cross-references remain reference nature only, and every generated page already flags this. Do not treat a placeholder OE number as a verified fitment claim.

What is honest to claim today

• Claim: the vehicle class and fitment-critical dimensions (thread, gasket, socket, panel dimensions) each SKU serves.
• Do not claim: specific make / model / year coverage, or that any XXXXX OE number is a verified match.

This page will be updated as the dataset matures from seed toward final.