> ## Documentation Index
> Fetch the complete documentation index at: https://docs.connectedfleet.michelin.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Tire Wear

Tire wear monitoring tracks the remaining tread depth (RTD) across your fleet to help predict tire replacements, identify abnormal wear patterns, and maintain compliance with safety regulations. Wear data is typically captured through drive-over scanners or manual inspection tools.

## Overview

The Smart Tire API provides two ways to access tire wear data:

* **Latest tire data** - Get the most recent wear measurements for one or more vehicles using the [Tire Events](/api-reference/tire/tire-events) endpoint with `inspectionTypes=TIRE_WEAR`
* **Wear history** - Get historical wear events for a specific vehicle over a date range using the [Tire Wear Events](/api-reference/tire/tire-wear-events) endpoint

## Remaining Tread Depth (RTD)

Tire wear is measured by the Remaining Tread Depth across multiple grooves on each tire:

| Field          | Unit   | Description                                                            |
| -------------- | ------ | ---------------------------------------------------------------------- |
| `grooveNumber` | -      | Index (starting from 1) identifying the specific groove being measured |
| `rtd`          | Meters | Remaining tread depth                                                  |

<Note>
  **Multiple groove measurements**

  Most commercial tires have 3-5 main grooves. Measuring each groove individually allows detection of uneven wear patterns that a single measurement would miss.
</Note>

### Wear Pattern Analysis

Multiple groove measurements help identify the cause of abnormal wear:

| Pattern            | Typical Cause       | Grooves Affected                    |
| ------------------ | ------------------- | ----------------------------------- |
| Center wear        | Over-inflation      | Center grooves worn more than edges |
| Edge wear          | Under-inflation     | Outer grooves worn more than center |
| One-sided wear     | Alignment issues    | Grooves on one side worn more       |
| Cupping/scalloping | Suspension problems | Irregular wear across grooves       |

## Tire Condition Flags

Each tire includes flags indicating special conditions:

| Flag        | Description                                                                                       |
| ----------- | ------------------------------------------------------------------------------------------------- |
| `regrooved` | Tire has been regrooved to extend service life by cutting new tread patterns into existing rubber |
| `retreaded` | Tire has been retreaded with new tread rubber applied to the casing                               |

<Info>
  Regrooved and retreaded tires have different wear characteristics and legal requirements. Tracking these flags helps ensure compliance with regulations governing their use.
</Info>

## Inspection Status

The `inspectionStatus` field indicates the validity and confidence level of wear measurements:

| Status                          | Description                                                |
| ------------------------------- | ---------------------------------------------------------- |
| `OK`                            | Valid inspection with reliable data                        |
| `MOUNT_CHANGE_SUSPICION`        | A tire change may have occurred since the last measurement |
| `INVALID_PROJECTION`            | Unable to project wear data accurately                     |
| `MISSING_POSITION`              | Position data unavailable                                  |
| `INVALID_UNDERLAYER`            | Issue with the tire's underlayer affecting measurement     |
| `POSITION_PASSAGE_TOO_OLD`      | Last passage through scanner is too old for reliable data  |
| `MOUNT_NEVER_SEEN`              | This specific tire mount has never been inspected          |
| `POSITION_NEVER_SEEN`           | This wheel position has never been inspected               |
| `VEHICLE_NEVER_SEEN`            | The vehicle has never passed through a scanner             |
| `DATE_OUT_OF_PROJECTION_PERIOD` | Measurement date falls outside valid projection window     |
| `UNSURE_WITHOUT_PASSAGE_DATE`   | Cannot confirm accuracy without passage date               |
| `NO_PROJECTION_DATA`            | Insufficient historical data for wear projection           |

<Warning>
  When `inspectionStatus` is anything other than `OK`, treat the wear data with caution. The measurement may be inaccurate or outdated.
</Warning>

## Tire Position

Each tire is identified by its position on the vehicle:

| Field                | Description                                                                 |
| -------------------- | --------------------------------------------------------------------------- |
| `axleNumber`         | Axle number starting from 1 (front axle)                                    |
| `tireCount`          | Total number of tires on that axle                                          |
| `tireNumber`         | Tire position on the axle, numbered from right to right when facing forward |
| `positionIdentifier` | String representation (e.g., "1L", "2R1", "2R2")                            |

## Event Data

Each wear event captures measurements for all tires at a specific inspection:

| Field       | Description                                                       |
| ----------- | ----------------------------------------------------------------- |
| `eventDate` | Timestamp of the wear inspection (UTC)                            |
| `tires`     | Array of tire data with position, groove measurements, and status |

## Use Cases

### Fleet-wide Wear Assessment

Retrieve the latest wear data for all vehicles to identify those approaching replacement thresholds:

```bash theme={null}
curl --request GET \
  --url 'https://public-api.masternautconnect.com/public/v1/customer/{customerId}/asset/tire?inspectionTypes=TIRE_WEAR' \
  --header 'Authorization: Bearer <your-api-token>'
```

### Wear Trend Analysis

Retrieve historical wear data to calculate wear rates and predict replacement dates:

```bash theme={null}
curl --request GET \
  --url 'https://public-api.masternautconnect.com/public/v1/customer/{customerId}/asset/{assetId}/tire/wear/history?startDate=2024-07-01&endDate=2025-01-01' \
  --header 'Authorization: Bearer <your-api-token>'
```

### Combined Pressure and Wear Data

Retrieve both inspection types in a single request for a complete tire health picture:

```bash theme={null}
curl --request GET \
  --url 'https://public-api.masternautconnect.com/public/v1/customer/{customerId}/asset/tire?inspectionTypes=TIRE_WEAR,TIRE_PRESSURE' \
  --header 'Authorization: Bearer <your-api-token>'
```

### Group-level Monitoring

Retrieve wear data for all vehicles within a specific group:

```bash theme={null}
curl --request GET \
  --url 'https://public-api.masternautconnect.com/public/v1/customer/{customerId}/asset/tire?inspectionTypes=TIRE_WEAR&groupId={groupId}' \
  --header 'Authorization: Bearer <your-api-token>'
```