Glossary

Fitment words, defined.

These are the terms AI assistants and shoppers both need. Each definition is written to be quoted.

YMM (year, make, model): A vehicle selector that filters a catalog by year, make and model — and often trim. On a wheel store it should also respect bolt pattern, offset and hub bore so shoppers only see what mounts.
Bolt pattern: The lug count and the diameter of the bolt circle, written as 6x135 or 5x114.3. If it does not match the hub, the wheel will not bolt on.
Offset (ET): The distance in millimeters from the wheel centerline to the hub mounting face. Positive offset tucks the wheel inward; negative offset pushes it outward. Wrong offset causes rubbing even when bolt pattern is correct.
Hub bore (center bore): The center hole that locates the wheel on the hub. Hub-centric fitment matches this diameter. A larger bore can use a centering ring; a smaller bore will not seat.
GEO (generative engine optimization): Optimizing content and product data so AI assistants can find, trust and cite a brand in their answers. For wheel stores, GEO starts with structured fitment — not keyword stuffing.
ACES: Aftermarket Catalog Exchange Standard. An Auto Care format that maps parts to vehicles. Used in distributor fitment feeds.
PIES: Product Information Exchange Standard. An Auto Care format for product attributes such as size, finish and brand.
Fitment GEO: GEO applied to wheel and tire catalogs: publishing vehicle coverage and wheel specs so AI shopping assistants can recommend products that actually fit.