Fuel Asset Reference

Intermediate40-60 minutesWindowsNotepad++Unity Editor

Fuel canisters are one of the essential utility item types in Unturned™ modding. A fuel asset defines a container that can hold, siphon, and deposit fuel - the resource that powers vehicles, generators, and certain mechanical devices across the game world. Fuel canisters are defined by the ItemFuelAsset class and are configured through a dedicated set of .dat fields that control capacity, spawn behavior, and consumption mechanics. Unlike consumable items that restore player stats, fuel canisters interact with the vehicle and generator systems, transferring their stored fuel into target fuel tanks when the player activates the canister while aiming at a compatible target.

57 Studios™ has documented and validated the full fuel asset configuration surface across the shipped game files and the official Smartly Dressed Games documentation. This article covers every .dat field that applies to fuel assets, the refueling mechanics that govern fuel transfer between the canister and its target, the Always_Spawn_Full and Delete_After_Filling_Target flags, and the complete field reference drawn from shipped game file evidence. The fuel asset shares the standard identity fields documented in Item Asset Anatomy; this article focuses on the fields that are unique to the ItemFuelAsset subclass and the runtime behavior they drive.

Documentation source: This article references the official Smartly Dressed Games modding documentation for field definitions and game behavior, specifically the ItemFuelAsset class documented in the Fuel Assets chapter. Shipped game file evidence from Bundles/Items/Fuels/ is cited for field values and patterns. Community-validated notes are marked where the official documentation is silent on a detail.

Who this article is for

This article is written for Unturned™ mod authors who are already familiar with the item .dat format and the master bundle pipeline. Readers should have completed at least one item mod of another type (weapon, consumable) before authoring a fuel asset. If you are new to Unturned™ modding, start with Project Folder Structure and GUIDs and Item Asset Anatomy before returning here. A working local Unturned™ install for in-game testing is required to verify fuel transfer behavior.

What you will learn

• Every .dat field available on the fuel asset type, including type, required status, default values, and purpose.
• How the fuel transfer mechanic works at the runtime level: which targets accept fuel, how the transfer amount is calculated, and what happens when the canister or target is full.
• The Always_Spawn_Full flag and its effect on loot generation versus crafted spawns.
• The Delete_After_Filling_Target flag and its use case for single-use fuel containers.
• How fuel capacity (Fuel field) relates to inventory size and game balance.
• How to author a complete fuel asset with a worked .dat example from shipped game file evidence.
• How to diagnose common fuel asset authoring errors using the diagnostic table.

How the fuel system works

The fuel system in Unturned™ is built around the UseableFuel script, which is the runtime handler for all fuel asset items. When a player equips a fuel canister and activates it while aiming at a compatible target (a vehicle with a fuel tank, a powered generator, or a fuel-powered mechanical device), the UseableFuel script reads the canister's .dat configuration and initiates a fuel transfer sequence. The sequence reads the canister's Fuel field to determine its maximum capacity, checks the current fuel level (tracked as an internal state on the item instance), and transfers fuel into the target's fuel tank until either the canister is empty or the target is full. Each unit of fuel transferred decrements the canister's internal fuel counter by one and increments the target's fuel counter by one.

The sequence above applies to every fuel canister in the game. The canister's Fuel field defines the maximum capacity; the actual fuel level at any given moment is tracked per-instance on the item's durability or fuel-state property. The Always_Spawn_Full flag determines the initial fuel state when the item is generated, and the Delete_After_Filling_Target flag determines whether the canister is consumed after a successful fuel transfer.

File structure for a fuel asset

A fuel asset follows the same folder structure as every other item asset in Unturned™:

FuelCanister/
├── Asset.dat           ← primary fuel asset definition (fields documented here)
├── English.dat         ← display name and description
└── FuelCanister.unity3d   ← master bundle containing the fuel canister prefab

The folder name, the Asset.dat filename stem, the bundle prefab name, and the internal Name field conventionally all match. The English.dat file follows the standard two-field format:

Name Portable Gas Can
Description Sizeable can of gasoline.

Shipped game files in Bundles/Items/Fuels/ follow this pattern exactly. The vanilla Gas canister uses ID 28, Gas_Large uses ID 1440, and the Jerrycan variants (Birch, Maple, Pine) use ID 1115. Each variant occupies its own subfolder with its own Asset.dat and English.dat.

Fuel-related targets

Fuel canisters can transfer fuel into the following target types:

Target type	Example	Fuel consumption behavior
Vehicle fuel tank	Car, truck, helicopter, boat	Fuel is consumed by the vehicle's engine when running. Vehicles without fuel cannot start.
Generator	Powered generator placement	Fuel is consumed by the generator when it is running. Generators without fuel cannot produce power.
Mechanical device	Fuel-powered pumps, spotlights (modded)	Fuel consumption varies by device configuration. Not all mechanical devices accept fuel; each device's asset definition must declare fuel compatibility.

Fuel compatibility is defined on the target's asset, not on the fuel canister. Any asset type that declares fuel acceptance through its own asset fields will accept fuel from any fuel canister - there is no caliber-style linkage for fuel types. All fuel canisters are universally compatible with all fuel-accepting targets.

Complete fuel .dat field reference

Identity and shared fields

The following shared fields are required on every item asset, including fuel canisters. See Item Asset Anatomy for full documentation of these fields, their types, and their valid enum values.

Field	Type	Example	Notes
ID	uint16	28	Unique item ID. Use the 50000+ range for custom mods.
GUID	uint128 hex	d5b9f19e2f2a4ee2ab4dc666f32f7df3	128-bit globally unique identifier. Generate a fresh GUID for every fuel asset.
Type	enum	Fuel	Must be Fuel for this asset type.
Name	string	Gas	Internal name; also the prefab lookup key.
Rarity	enum	Uncommon	Rarity tier. Shipped fuel canisters use Uncommon (standard) or Rare (large capacity).
Useable	enum	Fuel	Must be Fuel for fuel canisters. This is the field that binds the asset to the UseableFuel runtime script.
Slot	enum	Any	Inventory slot. Fuel canisters use Any or omit the field.
Size_X	uint8	2	Inventory grid width. Shipped canisters use 2 or 3.
Size_Y	uint8	2	Inventory grid height. Shipped canisters use 2 or 3.
Bypass_ID_Limit	bool	True	Required for IDs above 2000.

Fuel-specific fields

The fields below are unique to the ItemFuelAsset class. They define the fuel canister's capacity and behavior during the fuel transfer sequence.

Field	Type	Required	Default	Example	Purpose
Fuel	uint16	Required	None	500	The maximum fuel capacity of the canister in arbitrary fuel units. This value is the total fuel the canister can hold when full. The canister's current fuel level is tracked per-instance and is a fraction of this maximum. Shipped values range from 275 (Jerrycan) to 2500 (Gas_Large).
Always_Spawn_Full	bool	Optional	False	True	When set to True, every instance of this fuel canister that is generated (spawned in loot, crafted, or given via command) starts at maximum fuel capacity. When False or omitted, spawned canisters start with a random fuel level that is typically a fraction of the maximum - the exact fraction is controlled by the server's loot configuration.
Delete_After_Filling_Target	bool	Optional	False	True	When set to True, the fuel canister is removed from the player's inventory after successfully transferring fuel to a target. This is the flag that produces single-use fuel containers - the canister is consumed when its fuel is deposited. When False or omitted, the canister remains in the inventory and can be refilled from fuel sources.

Fuel capacity values from shipped game files

The table below documents every shipped fuel canister in the vanilla game files, as of the current stable Unturned™ release. Mod authors can use these values as balance references for custom fuel assets.

Asset	ID	Rarity	Fuel capacity	Size_X	Size_Y	Always_Spawn_Full	Delete_After_Filling_Target
Gas (Portable Gas Can)	28	Uncommon	500	2	2	Not set	Not set
Gas_Large	1440	Rare	2500	3	3	Not set	Not set
Jerrycan (Birch / Maple / Pine)	1115	Not set (Common)	275	2	2	Not set	Not set

Each Jerrycan variant (Birch, Maple, Pine) uses identical fuel configuration fields with the same ID 1115. The variants differ only in material appearance (the wood type of the Jerrycan model), demonstrating that fuel assets can share mechanical properties while providing visual variety through the master bundle's material assignments.

The flowchart above shows the three fuel capacity tiers present in the shipped game files. The capacity is roughly correlated with inventory footprint: larger fuel containers hold more fuel but consume more inventory grid cells.

Always_Spawn_Full in detail

The Always_Spawn_Full flag affects how the fuel canister's initial fuel state is determined when the item enters the game world. When the flag is absent or set to False, a spawned fuel canister starts with a randomized fuel level. The randomization range is determined by the server's loot multiplier settings and the item's spawn table configuration. A canister spawned with a low fuel level is functionally identical in appearance to a full canister - the fuel state is not visible in the inventory icon - which means a player who picks up a partially-full canister discovers its actual fuel level only when they attempt to transfer fuel.

When Always_Spawn_Full is set to True, every spawned instance of the canister starts at its maximum Fuel value. This is the appropriate configuration for rare fuel canisters that are intended as guaranteed rewards (quest items, special loot containers, admin-spawned supplies) and for fuel canisters that are crafted by players (crafting always produces a full canister regardless of this flag, because crafting consumes explicit input items to produce an explicit output).

Always_Spawn_Full and crafted items

Crafted fuel canisters always spawn at full capacity regardless of the Always_Spawn_Full flag. The flag only affects loot-table spawns and command-spawned items. A fuel canister that is crafted from blueprints will always appear with its full Fuel capacity because the crafting system creates a new item instance at its default state, and the default state for the UseableFuel class is full. The flag is therefore primarily relevant for loot-distribution design rather than crafted-item design.

Delete_After_Filling_Target in detail

The Delete_After_Filling_Target flag transforms a fuel canister from a reusable container into a single-use consumable. When the flag is set to True and the player successfully transfers fuel to a target, the canister item is removed from the player's inventory after the transfer completes. This is the correct flag for single-use fuel containers such as fuel pouches, jerrycans that are designed to be used once and discarded, or emergency fuel supplies that are consumed entirely upon use.

The deletion occurs only after a successful transfer. If the player activates the canister while no compatible target is in range, the canister is not deleted. If the target's fuel tank is already full, the transfer is not initiated and the canister is not deleted. The deletion is triggered by the completion of a fuel transfer operation that moves at least one unit of fuel from the canister to the target.

Shipped fuel canisters do not use this flag. All vanilla fuel canisters are reusable - the player fills them at a fuel source (a gas pump, a fuel barrel, a siphoning operation on another vehicle) and empties them into vehicles or generators, and the same canister can be refilled and reused indefinitely. The Delete_After_Filling_Target flag is available for mod authors who want to create a different gameplay experience: disposable fuel containers that are found in loot, used once, and consumed.

Worked example: standard fuel canister

The example below is modelled on the shipped Gas.dat (Portable Gas Can) with a custom ID and GUID for mod use. This configuration produces a standard reusable fuel canister with medium capacity.

ID 50050
GUID a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d
Type Fuel
Name CustomGasCan
Rarity Uncommon
Useable Fuel
Slot Any
Size_X 2
Size_Y 2

Bypass_ID_Limit True

Fuel 500

Companion English.dat:

Name Custom Gas Can
Description A reusable fuel canister holding 500 units of gasoline. Can be refilled at fuel pumps.

This configuration creates a fuel canister that:

• Holds 500 units of fuel when full.
• Spawns with a randomized fuel level (the Always_Spawn_Full flag is omitted).
• Remains in the player's inventory after transferring fuel (the Delete_After_Filling_Target flag is omitted).
• Occupies a 2-by-2 grid in the inventory.
• Is Uncommon rarity, making it a moderately common loot find.

Worked example: large capacity fuel canister

The example below is modelled on the shipped Gas_Large.dat with a custom ID and GUID. This configuration produces a large, rare, reusable fuel canister with substantial capacity.

ID 50051
GUID b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e
Type Fuel
Name CustomLargeGasCan
Rarity Rare
Useable Fuel
Slot Any
Size_X 3
Size_Y 3

Bypass_ID_Limit True

Fuel 2500

Companion English.dat:

Name Large Custom Gas Can
Description A high-capacity fuel canister holding 2500 units of gasoline. Rare and valuable.

The large canister occupies a 3-by-3 inventory grid - nine total cells - which is a significant footprint. The balance trade-off is between fuel capacity (five times the standard canister) and inventory space (more than double the area). Mod authors should match the inventory size to the capacity: a canister that holds five times the fuel should occupy proportionally more space, or the inventory-management gameplay is weakened.

Worked example: single-use fuel pouch

The example below demonstrates the Delete_After_Filling_Target flag with Always_Spawn_Full to create a disposable emergency fuel supply.

ID 50052
GUID c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f
Type Fuel
Name EmergencyFuelPouch
Rarity Common
Useable Fuel
Slot Any
Size_X 1
Size_Y 1

Bypass_ID_Limit True

Fuel 150
Always_Spawn_Full True
Delete_After_Filling_Target True

Companion English.dat:

Name Emergency Fuel Pouch
Description A single-use fuel pouch containing 150 units of gasoline. Consumed entirely when used.

This single-use fuel pouch is a common-rarity item that always spawns with its full 150-unit capacity. When the player transfers the fuel to a vehicle or generator, the pouch is consumed and removed from inventory. The 1-by-1 inventory footprint is tiny, reflecting the disposable nature of the container. This pattern is appropriate for emergency fuel supplies found in roadside loot spawns or as quest rewards.

Fuel capacity balancing considerations

The fuel capacity of a custom fuel canister should be balanced against the fuel tank capacity of the vehicles and generators in the target mod or map. A canister that carries more fuel than the target's tank can accept will always leave the target full and return the canister with remaining fuel. A canister that carries very little fuel relative to the target's tank will require multiple trips to a fuel source.

The table below provides cohort-recommended fuel capacity ranges by gameplay context:

Gameplay context	Recommended Fuel range	Rationale
Single-player survival	200-500	Players refuel one vehicle at a time; medium capacity encourages planning
Multiplayer survival	500-1000	Multiple vehicles per base; larger capacity reduces refueling downtime
PvP / raiding	100-300	Fuel is a tactical resource; smaller capacity creates scarcity tension
Creative / admin	2500+	Large capacity for testing and building without refueling friction
Quest item	50-150	Small, intentional capacity; fuel is a delivery quantity not a resource pool
Economy server	100-500	Tuned to server-specific fuel pricing; mod authors should consult server documentation

The values above are guidelines, not engine constraints. The Fuel field accepts any uint16 value from 0 to 65535. A canister with Fuel 0 is technically valid but carries no fuel and cannot transfer any. A canister with Fuel 65535 is effectively bottomless for most gameplay scenarios.

Fuel canister prefab considerations

The fuel canister prefab follows the same master bundle pipeline as any other item asset. The minimum prefab structure is a root GameObject with the InteractableItem script (or equivalent item interaction component) and a child MeshRenderer for the canister model. The prefab is not required to have any fuel-specific components - the UseableFuel runtime handler manages the fuel transfer logic entirely through code, independent of the prefab hierarchy.

The cohort recommendation for fuel canister prefab authoring:

• Model the canister at a scale that matches its inventory footprint. A large canister (3x3) should appear proportionally larger than a small canister (1x1) in the world and in the inventory view.
• Include a fuel cap or nozzle detail on the model to visually communicate the canister's function. Players should be able to identify a fuel item by its silhouette.
• Keep the polygon budget below 2000 tris for the canister body. Fuel canisters are simple geometric shapes - cylinders, cans, jerrycans - and do not require detailed sub-meshes.
• Use a PBR material with metallic and roughness properties. Fuel canisters are typically metal containers and should reflect light appropriately.

Fuel asset field authoring workflow

The cohort workflow for authoring a new fuel asset from scratch:

1. Assign a fresh ID. Choose an ID in the mod's assigned range (50000+). Confirm it is not used by any other item in the project.
2. Generate a GUID. Run [guid]::NewGuid().ToString("N") in PowerShell and paste the result into the GUID field.
3. Set the required fields. Type Fuel, Useable Fuel, and the identity fields.
4. Set the fuel capacity. Choose a Fuel value based on the gameplay context table above.
5. Configure spawn behavior. Add Always_Spawn_Full if the canister should always spawn full. Omit it if random fuel levels are acceptable.
6. Configure consumption behavior. Add Delete_After_Filling_Target only if the canister should be consumed on use.
7. Set inventory fields. Choose Size_X and Size_Y to match the canister's visual size and balance expectations.
8. Author English.dat. Write a user-facing name and description that communicates the canister's fuel capacity and any special properties (single-use, full-spawn, rare).
9. Author the prefab. Ensure the bundle contains the canister model prefab at the correct name.
10. Test in-game. Spawn the canister, fill it (if not Always_Spawn_Full, use a fuel pump or admin command to fill it), and transfer fuel to a vehicle or generator. Verify the fuel counter decrements on the canister and increments on the target.

Frequently asked questions

What happens if Fuel is set to 0?

A fuel canister with Fuel 0 is technically valid but carries no fuel capacity. The canister spawns empty, cannot be filled, and cannot transfer fuel to any target. This is not a useful configuration for a standard fuel canister. Set Fuel to at least 1 for any functional fuel item.

Can a fuel canister be refilled by the player?

Yes. A fuel canister without Delete_After_Filling_Target can be refilled from any fuel source in the game world: a gas pump at a service station, a fuel barrel, or by siphoning fuel from another vehicle. The refueling interaction is handled by the UseableFuel runtime - the player activates the canister while aiming at a fuel source, and the source's fuel is transferred into the canister. The canister's capacity (Fuel) is the maximum it can hold; the refueling operation stops when the canister reaches its capacity.

Can a vehicle be refueled directly without a canister?

Not through standard gameplay mechanics. The fuel transfer system in Unturned™ requires a fuel canister as the intermediate container. A vehicle's fuel tank cannot be filled directly from a fuel pump or fuel barrel - the player must fill a canister from the source, then transfer the canister's fuel into the vehicle. This two-step process is an intentional gameplay design that makes fuel management a meaningful logistical consideration.

Does the canister model in the world reflect its fuel level?

No. The fuel level of a canister is tracked as internal data on the item instance and is not reflected in the world model or the inventory icon. A canister that is empty (0 fuel remaining) looks identical to a canister that is full (Fuel capacity). The player must equip the canister or inspect its tooltip to see the current fuel level. This is an engine limitation; mod authors cannot add visual fuel-level indicators to the vanilla fuel canister system without server-side scripting.

How do I make a fuel canister that can only be used once?

Set Delete_After_Filling_Target True in the .dat file. The canister will be consumed and removed from the player's inventory after it successfully transfers fuel to a target. Pair this with Always_Spawn_Full True if the canister should always appear with its full capacity when found in loot. This pattern is documented in the single-use fuel pouch worked example above.

Can I make a fuel canister that is not refillable?

Not through the standard .dat fields alone. The fuel asset system does not have a "not refillable" flag. A canister without Delete_After_Filling_Target is always refillable. To create a non-refillable fuel container, set Delete_After_Filling_Target True and give the canister a very small Fuel value - the canister will be consumed after its single transfer, which effectively makes it non-refillable because the item no longer exists after use. This is a workaround, not a dedicated flag, and should be documented in the item description so players understand the behavior.

What is the maximum value for the Fuel field?

The Fuel field is a uint16, so its maximum value is 65535. A fuel canister with Fuel 65535 holds approximately 131 times the capacity of the standard Gas canister (500). Values this high are appropriate only for admin items, debug tools, or creative-mode scenarios where fuel management is not a gameplay concern. For standard mod use, values between 100 and 2500 cover the full range of reasonable gameplay contexts.

Can a fuel canister be used as a weapon (thrown or shot)?

No. Fuel canisters are Useable Fuel items, which means they are activated for fuel transfer, not for combat. A fuel canister cannot be thrown, shot, or detonated through its .dat configuration. If the mod design requires an explosive fuel container, author it as a throwable asset with explosive properties and use the fuel canister model as the prefab - the gameplay behavior comes from the throwable asset type, not from the fuel configuration.

Do fuel canisters stack in inventory?

No. Fuel canisters do not stack in the vanilla inventory system. Each canister occupies its own inventory grid cells (defined by Size_X and Size_Y). The fuel level is tracked per-instance on each canister, so stacking would lose the individual fuel state information. If inventory economy is a concern, the cohort recommendation is to use smaller canisters with lower capacity rather than relying on stacking.

Why does my fuel canister show as empty when I spawn it?

A spawned fuel canister starts with a randomized fuel level unless Always_Spawn_Full is set to True. The randomization range depends on the server's loot multiplier settings. If the canister is spawned via the @give command without Always_Spawn_Full True, it will spawn with a random fuel level - which could be very low or even zero. To guarantee a full canister on spawn, add Always_Spawn_Full True to the .dat file.

Can a fuel canister transfer fuel into another fuel canister?

No. The fuel transfer system targets vehicle fuel tanks and generators, not other fuel canisters. Players cannot transfer fuel from one canister to another through the standard gameplay interaction. To move fuel between canisters, the player must use a fuel source as the intermediary: empty Canister A into a vehicle, then fill Canister B from the same vehicle's tank (using the siphon mechanic available in some game modes).

Does the fuel canister model need to show fuel inside it?

No. The fuel canister model is a static mesh; the fuel level is tracked as internal per-instance data and is not reflected in the world model. A canister that is completely empty looks identical to one that is completely full. The only visual indication of fuel content is the tooltip text, which displays the current fuel level as a fraction of the maximum capacity.

Can I make a fuel canister that works with only one specific vehicle type?

Not through the fuel asset .dat fields. Fuel canisters are universally compatible with all fuel-accepting targets. There is no field on the fuel asset to restrict compatibility to specific vehicle types, generator models, or mechanical devices. If a mod requires a vehicle-specific fuel canister, the restriction must be enforced at the vehicle asset level (by making the vehicle's fuel tank accept only specific item IDs) or through server-side scripting. The fuel asset itself cannot declare target restrictions.

How does the fuel canister interact with the engine's item decay system?

Fuel canisters participate in the item decay system like any other item type. If the server has item decay enabled, a fuel canister that remains in the world (dropped or stored in a container that does not prevent decay) will degrade and eventually despawn. The decay timer is configured by the server's Item_Decay_Time setting and is not affected by the fuel canister's Fuel value or current fuel level. A full canister decays at the same rate as an empty canister. Mod authors who want a fuel canister to be permanent should note that decay behavior is controlled by server configuration, not by the .dat file.

Can I create a fuel canister that requires a specific skill level to use?

Not through the fuel asset .dat fields. The fuel canister does not have a skill requirement field. Skill requirements for item use are configured through the blueprint system (for crafted items) or through the server's plugin system. A fuel canister that requires a minimum skill level to craft can be enforced by the blueprint's Skill and Skill_Level fields, but once the canister is in a player's inventory, any player can activate it to transfer fuel regardless of their skill levels. If skill-gated fuel use is required, it must be implemented through server-side scripting.

Diagnostic table

Symptom	Most likely cause	Resolution
Fuel canister does not appear in inventory after @give	ID mismatch or .dat in wrong folder	Confirm ID in command matches ID in .dat; check folder path
Fuel canister appears but cannot be equipped	Useable Fuel missing from .dat	Add Useable Fuel to the .dat file
Fuel transfer does not start when activating canister	No compatible target in range or crosshair not on target	Aim directly at a vehicle or generator fuel tank
Fuel transfer starts but no fuel moves	Fuel value is 0	Set Fuel to a positive value (e.g., 500)
Canister always spawns empty	Always_Spawn_Full not set, or server loot multiplier is very low	Add Always_Spawn_Full True if full spawn is desired
Canister disappears after one use	Delete_After_Filling_Target set unexpectedly	Remove the Delete_After_Filling_Target flag for a reusable canister
Canister fuel level does not display in tooltip	Vanilla engine limitation; fuel level is internal data	Use a UI mod that exposes fuel level on item tooltips
Pink material on canister model	Shader missing or material not assigned in bundle	Re-assign material in Unity, rebuild bundle
Canister model is invisible when equipped or dropped	Prefab reference broken in master bundle	Re-assign prefab in Unity, rebuild bundle
Canister does not interact with a specific vehicle	Vehicle asset may not declare fuel compatibility	Check the vehicle's .dat for fuel tank configuration fields
Canister shows wrong size in inventory	Size_X or Size_Y set incorrectly	Correct the size fields to match the model's visual footprint

Best practices

• Generate a fresh GUID for every fuel asset. Never reuse GUIDs from other items or other mods.
• Choose IDs in the 50000+ range to avoid collision with vanilla IDs (28-1440 range) and established community mods.
• Match inventory size to fuel capacity: a large fuel canister should occupy more grid cells than a small one.
• Use Always_Spawn_Full sparingly. The randomized fuel level on loot spawns creates interesting gameplay tension.
• Use Delete_After_Filling_Target intentionally. Single-use fuel canisters are a deliberate design choice, not a default behavior.
• Author the prefab with a clear fuel-canister silhouette. Players should recognise the item type by its shape.
• Test fuel transfer against both a vehicle and a generator before publishing. The two target types share the same fuel system but have different visual feedback.
• Document the fuel capacity in the English.dat description so players know what they are picking up.
• Keep fuel capacity values within the 100-2500 range for standard gameplay contexts. Higher values dilute fuel management as a gameplay mechanic.
• Verify Useable Fuel is present in every fuel asset .dat. This is the single most common omission in new fuel asset mods.

Advanced considerations

Fuel canisters with blueprint crafting recipes

Fuel canisters can be made craftable through the blueprint system. The shipped Jerrycan_Birch demonstrates blueprints that allow crafting the jerrycan from planks and tape. Blueprints are added to the .dat file using the blueprint block syntax. A fuel canister blueprint consumes input materials and produces the fuel canister as the output. The crafted canister appears at full fuel capacity regardless of the Always_Spawn_Full flag, because crafting creates a fresh item instance at its default state.

Fuel canisters as quest or scenario items

Fuel canisters with very low capacity (Fuel 10-50) and Always_Spawn_Full True serve well as quest items or scenario objectives - a quest that requires the player to deliver fuel to a generator, for example. For this use case, set the capacity to exactly the amount the quest requires, so the canister is fully consumed when the quest target is refueled. Pair with Delete_After_Filling_Target True if the quest item should be consumed as part of the objective completion.

Multiple fuel canister sizes in a single mod

A well-balanced mod series provides fuel canisters in multiple capacity tiers, matching the gameplay context. The cohort pattern is three tiers: small (100-275, 1x1 or 2x1), medium (300-500, 2x2), and large (1000-2500, 3x3). Each tier has a different rarity and inventory footprint, giving players meaningful choices about how much inventory space to dedicate to fuel.

Fuel canisters in PvP and raid contexts

On PvP servers, fuel canisters serve a double role: they are both a resource for powering vehicles and a potential raid tool (fueling a vehicle used to ram or blockade enemy bases). The cohort recommendation for PvP-focused fuel canisters is to keep capacity moderate (100-300) and to add Always_Spawn_Full True so that fuel found in loot is immediately useful rather than requiring a trip to a fuel pump.

Fuel canisters and the durability system

Fuel canisters do not use the durability system. The Durability and Wear fields from other item types do not apply to fuel assets. The fuel canister's wear is its fuel level - a canister with zero fuel is functionally spent, but unlike a melee weapon's durability, the fuel canister is not destroyed at zero fuel; it remains in the inventory and can be refilled. Setting Durability or Wear on a fuel asset has no effect on the fuel transfer system.

Fuel canister skin support

Fuel canisters support cosmetic skin variants through the Steam item economy system, following the same pattern as other item types. Skin variants change the material appearance of the canister prefab but do not affect the Fuel, Always_Spawn_Full, or Delete_After_Filling_Target fields. Skin support is configured in the Economy.dat alongside the standard item .dat and is relevant primarily for commercial mods distributed through the Workshop marketplace.

Appendix A: Fuel asset .dat quick-reference template

Copy this template for a new fuel asset. Delete fields that do not apply to the specific canister design.

ID <50000+>
GUID <generated-uuid-no-hyphens>
Type Fuel
Name <InternalFuelCanisterName>

Rarity <Common|Uncommon|Rare>
Useable Fuel
Slot Any
Size_X <2>
Size_Y <2>

Bypass_ID_Limit True

Fuel <500>
Always_Spawn_Full <True|omit>
Delete_After_Filling_Target <True|omit>

Appendix B: Fuel capacity balance comparison table

Capacity tier	Fuel value	Rarity	Size_X	Size_Y	Use case
Very small	25-50	Common	1	1	Quest item, emergency puff
Small	100-275	Common	1	1	Disposable fuel pouch, jerrycan
Medium	300-600	Uncommon	2	2	Standard fuel canister
Large	1000-1500	Rare	2	2	Extended fuel canister
Very large	2000-3000	Rare	3	3	Bulk fuel transport
Extreme	5000+	Epic	4	3	Admin / creative only

Appendix C: External references

Resource	URL	Notes
Smartly Dressed Games modding documentation	https://docs.smartlydressedgames.com/en/stable/	Official field reference for ItemFuelAsset.
Unturned on Steam	https://store.steampowered.com/app/304930/Unturned/	Game changelog and community hub.
Item Asset Anatomy	/items/item-asset-anatomy	Shared field reference for all item types, including fuel assets.
Refill Asset Reference	/items/refill-asset-reference	The next article; covers water canister assets that share structural patterns with fuel assets.
Vehicle Repair Tool Reference	/items/vehicle-repair-tool-reference	The previous article; covers the vehicle repair tool asset type.
Project Folder Structure and GUIDs	/items/project-folder-structure-and-guids	GUID generation and folder layout for all item mods.
Master Bundle Export	/items/master-bundle-export	The Unity bundling workflow used to package fuel canister prefabs.

Cross-references

• Item Asset Anatomy - the shared field reference for all item types, including the identity fields used by fuel assets.
• Refill Asset Reference - the water canister asset type, which shares the useable-item structural pattern with fuel canisters.
• Vehicle Repair Tool Reference - the previous article; covers the vehicle interaction item type.
• Food, Water, and Medical Items - consumable item types that share the identity field set with fuel assets.
• Project Folder Structure and GUIDs - GUID generation and folder layout conventions for all item types.
• Master Bundle Export - the Unity bundling pipeline for packaging item prefabs, including fuel canister models.
• Smartly Dressed Games modding documentation - official field reference for the ItemFuelAsset class.
• Unturned on Steam - game page and community.

Authoring checklist

Before publishing a fuel asset mod, confirm the following:

• [ ] GUID is unique - generated fresh, not copied from another asset
• [ ] ID is in the 50000+ range
• [ ] Type Fuel is present
• [ ] Useable Fuel is present
• [ ] Fuel is set to a positive value (1 or higher)
• [ ] Always_Spawn_Full is present if full-spawn behavior is desired
• [ ] Delete_After_Filling_Target is present only if single-use behavior is intended
• [ ] Size_X and Size_Y match the intended inventory footprint
• [ ] Bypass_ID_Limit True is present if ID exceeds 2000
• [ ] English.dat is authored with Name and Description fields
• [ ] Master bundle contains the fuel canister prefab at the correct name
• [ ] Tested in single-player: canister spawns, equips, transfers fuel to vehicle and generator
• [ ] Fuel transfer decrements canister and increments target as expected
• [ ] If Always_Spawn_Full is set, spawned canisters appear at full capacity
• [ ] If Delete_After_Filling_Target is set, canister is consumed after transfer

Document history

Version	Date	Author	Notes
1.0	2026-07-26	57 Studios	Initial publication. Full fuel asset .dat field reference, fuel transfer mechanics, worked examples, FAQ, diagnostic table, appendices.