Understanding Fitment Data

FitmentPro uses a structured vehicle hierarchy to organize compatibility data. Understanding this hierarchy is key to using the app effectively.

The Vehicle Hierarchy (5 Stages)

Every vehicle in the database is classified using five levels:

Brand (320+ brands) — The manufacturer (e.g., BMW, Toyota, Volkswagen)
Model (6,700+ models) — The model line (e.g., 3 Series, Corolla, Golf)
Variant (35,000+ variants) — The specific variant (e.g., 320i, 1.8 VVT-i, GTI)
Platform (28,500+ platforms) — The technical platform code (e.g., F30, E210, MK8)
Year (48,000+ year entries) — The production year range (e.g., 2019–2023)

What is a Fitment Rule?

A fitment rule is a single record that says "this product is compatible with this vehicle." Each rule contains:

Brand, model, variant, and platform information
Year range (from/to)
Engine details (displacement, power, fuel type)
KType number (TecDoc reference)
Optional HSN/TSN (German registration codes)

How Rules Are Stored

FitmentPro stores fitment data in Shopify metafields on each product:

vehicle_fitment.rules — The full fitment data in JSON format (used by theme blocks to display compatibility)
vehicle_fitment.search — Indexed values for Shopify's native search (so customers can search "BMW 3 Series" and find matching products)
Filter metafields — Separate metafields for brand, model, variant, platform, year_min, and year_max (used for Shopify collection filters)

Large Fitment Lists

Products with many compatible vehicles (350+ rules) are automatically split across multiple metafield chunks (rules, rules_2, rules_3, etc.) to stay within Shopify's 60KB metafield limit. This happens transparently — you don't need to manage it.

The TecDoc Database

FitmentPro's vehicle database comes from TecDoc, the automotive industry standard. Each vehicle has a unique KType number that precisely identifies a specific vehicle configuration. The database contains 55,647 unique KType records.