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

# Truck and trailer routing and fuel specs

> What each routing and fuel field on a truck or trailer means, its units and limits, and how to show the spec columns on the Trucks and Trailers lists.

## Overview

Trucks and trailers in Alvys hold routing and fuel specs: their dimensions, weight ratings, axle and tire counts, and fuel details. Alvys uses these specs for routing and cost estimates. Every field is optional. A field you leave blank, or clear, is not set.

You enter truck specs in the **Routing & Fuel** section of the truck form. You enter trailer specs in the **Routing Specs** section of the trailer form, which has a **Reefer** sub-section for reefer equipment types.

## Before you start

You must have the **"EditAsset"** permission to add or change specs on a truck or trailer. Without it, you cannot add or edit trucks and trailers.

## Add specs to a truck

1. In the left navigation bar, select **Assets**, then click **Trucks**.
2. Open a truck from the list, or click **New Truck** to create one.
3. Scroll to the **Routing & Fuel** section and fill in the specs you know.
4. Save the truck. For a new truck, click **Add Truck**.

![Shows the Routing & Fuel section of the truck form with example values in Tire Count, Height, Width, Length, GCWR, Fuel Kind, MPG Loaded, MPG Empty, Tank Capacity (per tank), and Tank Count](https://mintlify.s3.us-west-1.amazonaws.com/alvys/images/help/67d147eb88a5.png)

*Shows the Routing & Fuel section of the truck form with example values in each field*

## Add specs to a trailer

1. In the left navigation bar, select **Assets**, then click **Trailers**.
2. Open a trailer from the list, or click **New Trailer** to create one.
3. Scroll to the **Routing Specs** section and fill in the specs you know. If the Equipment Type is a reefer type, also fill in the **Reefer** sub-section.
4. Save the trailer. For a new trailer, click **Add Trailer**.

![Shows the Routing Specs section of the trailer form with example values in Height, Width, Length, Axle Count, Tire Count, Empty Weight, and GVWR, and the Reefer sub-section with Reefer Fuel Burn and Reefer Tank Capacity](https://mintlify.s3.us-west-1.amazonaws.com/alvys/images/help/311e54848906.png)

*Shows the Routing Specs section of the trailer form, with its Reefer sub-section, filled in with example values*

## Truck fields

Each field shows its description when you hover over it.

![Shows the description of the GCWR field that appears when you hover over it: Gross Combination Weight Rating, the most the truck, trailer and cargo may weigh together](https://mintlify.s3.us-west-1.amazonaws.com/alvys/images/help/b678f2f28239.png)

*Shows the description that appears when you hover over the GCWR field*

| Field | Description | Units and limits |
| - | - | - |
| **Tire Count** | Total number of tires on the truck, steer and drive axles combined. Used in the routing vehicle profile. | Whole number, 2 to 40 |
| **Height** | Overall height of the truck from the ground to its highest point. Routing uses it to avoid low bridges and overpasses. | ft, in, yd, or m. More than 0, up to 20 ft (240 in) |
| **Width** | Overall width of the truck, not counting mirrors. Routing uses it to avoid width-restricted roads. | ft, in, yd, or m (starts in inches). Up to 16 ft |
| **Length** | Overall length of the truck only. Enter the trailer's length on the trailer. Routing uses it to check length-restricted roads. | ft, in, yd, or m. Up to 100 ft |
| **GCWR** | Gross Combination Weight Rating: the most the truck, trailer and cargo may weigh together, set by the manufacturer. Use it to check what the truck can pull. | lbs. Up to 200,000 lbs |
| **Fuel Kind** | The fuel this truck burns. Used to price fuel in trip cost estimates. | Diesel, Gasoline, CNG, LNG, Electric, or Hybrid |
| **MPG Loaded** | Average miles per gallon while hauling a load. Used to estimate fuel cost on loaded miles. | mpg. More than 0, up to 30 |
| **MPG Empty** | Average miles per gallon while running empty (deadhead). Used to estimate fuel cost on empty miles. | mpg. More than 0, up to 30 |
| **Tank Capacity (per tank)** | How much fuel one tank holds. With Tank Count, sets the truck's fuel range. | Gallons. Up to 500 |
| **Tank Count** | Number of fuel tanks on the truck. | Whole number, 1 to 4 |

## Trailer fields

Each field shows its description when you hover over it.

| Field | Description | Units and limits |
| - | - | - |
| **Height** | Overall height of the trailer from the ground to its highest point. Routing uses it to avoid low bridges and overpasses. | ft, in, or m. More than 0, up to 20 ft (240 in) |
| **Width** | Overall width of the trailer. Routing uses it to avoid width-restricted roads. | ft, in, or m (starts in inches). Up to 16 ft |
| **Length** | Overall length of the trailer. Routing uses it for length rules such as the 53-foot trailer limit. | ft, in, or m. Up to 100 ft |
| **Axle Count** | Number of axles on the trailer. Tolls are often priced by the total axle count of the truck and trailer. | Whole number, 1 to 13 |
| **Tire Count** | Total number of tires on the trailer. Used in the routing vehicle profile. | Whole number, 2 to 60 |
| **Empty Weight** | Weight of the empty trailer with no cargo (tare weight). | lbs. Up to 100,000 lbs |
| **GVWR** | Gross Vehicle Weight Rating: the maximum loaded weight of the trailer, set by the manufacturer. | lbs. Up to 200,000 lbs, and at least the Empty Weight |
| **Reefer Fuel Burn** | Fuel the reefer unit uses per hour while it runs. Used to estimate reefer fuel cost. | Gallons per hour. More than 0, up to 3 |
| **Reefer Tank Capacity** | How much fuel the reefer unit's tank holds. | Gallons. Up to 200 |

The **Reefer** sub-section shows only when the trailer's Equipment Type is a reefer type. If you change the Equipment Type to a type that is not a reefer, the reefer values you already entered are kept.

## Units, limits, and blank fields

* **Every field is optional.** Leave a field blank, or clear it, and it is not set.
* **Height, Width, and Length have a unit list** next to the field. On a truck, select ft, in, yd, or m. On a trailer, select ft, in, or m. Width starts in inches on both.
* **Out-of-range values show a message** under the field. For example: *"Height must be greater than 0 and at most 20 feet (240 in)."* Correct the value, or clear the field.
* **Number fields accept only digits**, and a decimal point where a fraction makes sense. You cannot type or paste the letter "e", a plus sign (+), or a minus sign (−).

## Tire size suggestions

Tire size fields suggest common sizes as you type. Select a size from the list, or keep typing to enter any other size. Tire sizes you saved before stay as they are.

* On a truck, **Steer Tire Size** and **Drive Axles Tire Size** suggest sizes such as 295/75R22.5, 11R22.5, and the wide-base 445/50R22.5.
* On a trailer, **Tire Size** suggests common trailer sizes, including low-deck 17.5" and 15" sizes.

![Shows the Steer Tire Size field with the list of suggested standard tire sizes open below it](https://mintlify.s3.us-west-1.amazonaws.com/alvys/images/help/1b2842160438.png)

*Shows the Steer Tire Size field with the list of suggested standard tire sizes open below it*

## Show the spec columns on the Trucks and Trailers lists

The Trucks and Trailers lists have a column for each spec. The columns are hidden until you turn them on.

1. Open **Assets** > **Trucks** or **Assets** > **Trailers**.
2. On the right edge of the list, click **Columns**.
3. Select the check box next to each spec column you want to show, for example **Height** or **Length**.

![Shows the Columns panel on the Trucks list, with the routing and fuel spec columns such as Height, Width, Length, GCWR, Tire Count, MPG Loaded, MPG Empty, Tank Capacity, Tank Count, and Fuel Kind not selected](https://mintlify.s3.us-west-1.amazonaws.com/alvys/images/help/56dd9999a57b.png)

*Shows the Columns panel on the Trucks list, with the routing and fuel spec columns not selected, which is how they start*

When you filter a spec column, Height and Length filter in feet and Width filters in inches. Each filter box shows its unit. Weights show in lbs and tank sizes in gallons.

## FAQs

**Q: Do I have to fill in the routing and fuel specs?**

**A:** No. Every field is optional, and you can save a truck or trailer with the specs left blank. You can add or change them later by editing the record.

**Q: Where do I enter the length of a truck and trailer combination?**

**A:** Enter each length on its own record. A truck's Length is the truck only. Enter the trailer's length on the trailer.

**Q: Do the new fields change Fuel Type, MPG, Gross Weight, or Max Weight?**

**A:** No. The existing truck fields (Number of Axles, Gross Weight, Empty Weight, Fuel Type, and MPG) and trailer fields (Equipment Type, Size, Pallet Capacity, Max Weight, and Tire Size) are unchanged and work as before.

**Q: Can I set routing and fuel specs through the Public API, EDI, or the mobile app?**

**A:** No. You set them on the truck and trailer forms in the Alvys web app.

## Go deeper

* [How to add a truck in Alvys](https://docs.alvys.com/en/help/assets-fleet/how-to-add-a-truck-in-alvys.md)
* [How to add a trailer](https://docs.alvys.com/en/help/assets-fleet/how-to-add-a-trailer.md)