Fitment data overview

Fitment data is the set of claims that link a SKU to a vehicle. WySync does not invent those claims — it collects them from wherever you keep them, merges them, and puts the result in front of the shopper.

The union rule#

A SKU fits a vehicle if any connected source says it does.

That is the whole model. There is no precedence order to configure, no source ranked above another, and no conflict resolution screen. It works because in practice every source is incomplete in a different direction: your tags cover the bestsellers, the supplier feed covers their own catalog, the spec data covers everything with clean measurements, and none of them covers all three.

The trade-off is honest and worth stating: a union propagates a source's mistakes as readily as its coverage. That is what the fitment editor is for — exclusions are applied after the merge and win.

The sources#

When resolution happens#

Fitment resolves at index time for mapping-style sources, and at query time for wheel and tire spec matching.

That distinction matters:

• Change a CSV, a tag or a sheet, and the storefront reflects it after the next index run — immediately if you press Reindex.
• Turn the Fitment Data add-on on or off and the change is instant, because spec matching is evaluated per request against the shopper's vehicle.

The three verdicts#

Whatever the source, a shopper's product page shows exactly one of:

Fits

at least one source confirms this SKU for the exact vehicle ID, or spec matching judges it inside the envelope.

Does not fit

you excluded it in the editor, or (wheels and tires with the add-on) spec matching positively rules it out. Only shown when the engine can actually judge.

Unconfirmed

nothing claims it and nothing can judge it. The default when you have no data, and configurable copy — most shops point at a phone number here.

The distinction between does not fit and unconfirmed is deliberate. For most categories the engine cannot prove a negative from a missing mapping — a brake kit with no row for a Tacoma might genuinely fit and simply be unmapped. Pretending otherwise turns absent data into lost sales.

Coverage, measured#

The Dashboard reports fitment coverage as the share of indexed products with at least one vehicle mapped or judgeable. Under about 60%, most shoppers will land on unconfirmed products and the funnel feels broken — that number is the one to watch in the first fortnight.