A free MCP server and API for wheel fitment data (bolt pattern, center bore, offset)

#mcp #ai #api #opendata

Ask an LLM "what wheels fit a 2024 Tacoma?" and you will usually get a confident answer that is half right. The bolt pattern is easy to find. The center bore, the one that changed on this generation, is where models guess.

We make custom forged wheels, so we keep a fitment table for our own production. We opened it up: a CSV dataset, a REST API and a remote MCP server, all free and without an API key.

What is in the data

10,093 vehicle variants, 174 makes, 56 bolt patterns (dataset version 2026.10.19)
Bolt pattern (PCD), lug count, center bore (front and rear where they differ)
Factory wheel size and offset, plus a "flush" and a "max" aftermarket size
A source page for every row, CC BY 4.0, DOI 10.5281/zenodo.23280367

Use it from an MCP client

The server speaks Streamable HTTP and needs no auth:

{
  "mcpServers": {
    "ankusi-wheel-fitment": {
      "url": "https://ankusiwheels.com/wp-json/ankusi/v1/mcp"
    }
  }
}

It exposes three read-only tools:

Tool	What it does
`lookup_wheel_fitment`	make + model (+ year) to bolt pattern, center bore, OE / flush / max wheel
`vehicles_by_bolt_pattern`	every vehicle on a given PCD, e.g. `5x120`, optional make filter
`list_makes`	the makes covered

It is also in the official MCP Registry as com.ankusiwheels/wheel-fitment.

Or call the REST API

curl "https://ankusiwheels.com/wp-json/ankusi/v1/fitment?make=Toyota&model=Tacoma&year=2024"

Trimmed response:

{
  "dataset_version": "2026.10.19",
  "license": "CC BY 4.0",
  "results": [
    {
      "model": "Toyota Tacoma",
      "year": "2024",
      "bolt_pattern": "6x139.7",
      "center_bore_mm": "95.1",
      "oe_wheel": "F/R 17x7.5J",
      "flush_wheel": "18x8.0J ET30",
      "max_wheel": "20x8.5J ET25"
    }
  ]
}

There is an OpenAPI 3 spec here: https://ankusiwheels.com/wp-content/uploads/ankusi-feeds/openapi.json

Why center bore matters

Grouping the dataset by bolt pattern shows how little the bolt pattern alone tells you:

Bolt pattern	Vehicles	Distinct center bores
5x114.3	2,073	16
5x112	1,963	6
5x120	947	18
6x139.7	510	19

Generation changes are the classic trap. The 2024 Tacoma kept 6x139.7 but its hub bore went from 106.1 mm to 95.1 mm. The C8 Corvette moved from 5x120.65 (C7) to metric 5x120. An assistant that only checks the PCD will say old wheels fit when they do not.

How the values are checked

Bolt pattern and center bore changes are only accepted when two independent references agree. Where sources conflict, the field is left blank rather than guessed, and every correction is logged in the changelog.

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