How to Track Fuel Usage Across Vehicles, Equipment and Sites

For most construction, infrastructure, and operations businesses, fuel combustion is the single largest source of Scope 1 greenhouse gas emissions. A large civil project might run 50 pieces of heavy plant through thousands of litres of diesel per day — and tracking that consumption accurately enough to support an assurance review requires more than a monthly summary from the fleet manager.

Here’s how to build a fuel tracking process that works.

Identify all your fuel sources

Fuel reaches your business through multiple channels, and each needs to be captured:

Fuel cards: The most common mechanism for vehicles. Cards are tied to vehicles or drivers, and statements are available monthly showing litres dispensed, date, and location. The data quality is usually good — fuel cards produce structured data.

Bulk fuel deliveries: Sites often have a diesel tank that’s replenished by tanker delivery. The delivery docket records volume delivered. Consumption is calculated as opening stock + deliveries − closing stock, which requires regular physical dips of the tank.

Bowser or drum purchases: Some sites purchase fuel in small volumes from service stations or drummed suppliers. These are often paid in cash or on a card and may not flow through a fuel card system. They’re the hardest to capture consistently.

Generator fuel: Sites using diesel generators for power need to track fuel consumed separately from mobile plant. Generator consumption is Scope 1 (direct combustion) and needs to be distinguished from mobile plant consumption because the emission factor category may differ.

Distinguish mobile vs stationary combustion

The NGA Factors use different emission intensities for:

• Mobile combustion (vehicles and mobile plant — excavators, trucks, cars): slightly higher
• Stationary combustion (generators, boilers, stationary plant): slightly lower

Using the wrong category will introduce a small but systematic error. If you have a mix of mobile and stationary diesel use, track them separately.

Attribute fuel to site and project

The critical requirement for project-level reporting is attribution. Every litre of fuel consumed needs to be attributed to:

• A site or project code
• A time period (for allocation to reporting periods)
• A plant item or vehicle (for allocation between projects if a machine moves between sites)

Fuel cards: If fuel cards are assigned by vehicle, and vehicles are assigned to projects, the attribution is relatively straightforward. Problems arise when vehicles work across multiple projects within a period.

Bulk deliveries: If a site tank supplies both on-highway trucks and on-site plant, consider whether you need to sub-meter or allocate the deliveries. The simplest approach is to treat all deliveries to a site tank as Scope 1 for that project.

Plant that moves between sites: Decide on an allocation method upfront: by calendar day, by hours logged, or by dockets associated with each project. Document the method.

Handle subcontractors carefully

Subcontractor fuel is a common source of confusion. Generally:

• If your subcontractor provides their own plant and fuel, their emissions are your Scope 3 (Category 1: purchased services), not your Scope 1
• If you supply fuel to a subcontractor for use in their plant on your site, it may be your Scope 1 — since you own or control the fuel

Which boundary you apply needs to be documented and applied consistently. Client requirements vary — some want all on-site fuel included regardless of who owns the plant; others use the operational control boundary strictly. Clarify with clients early.

Calculate the emissions

Diesel, mobile combustion: Litres × NGA mobile combustion factor for diesel = kg CO₂e

Diesel, stationary combustion: Litres × NGA stationary combustion factor for diesel = kg CO₂e

Petrol, mobile combustion: Litres × NGA mobile combustion factor for petrol = kg CO₂e

LPG, mobile: Litres × NGA mobile combustion factor for LPG = kg CO₂e

Record the specific NGA Factors version and table reference for each factor applied. The emission factors are updated annually and the version matters for assurance.

Dealing with incomplete data

Fuel data is often incomplete — a month with no bulk delivery docket, a fuel card that wasn’t used for on-site plant, a period of unrecorded generator use.

For gaps in fuel card data: Estimate based on the vehicle’s average consumption in comparable periods, and flag the estimate in the dataset. Don’t omit the period entirely.

For bulk tank gaps: Require monthly physical dips (stock counts) to calculate consumption from movements, even if deliveries weren’t made. A dip record on the first and last day of each reporting period is minimum best practice.

For generator fuel: If generator hours are logged but fuel is not measured, use the manufacturer’s consumption specification (litres per hour at rated load) as an estimate. Document the basis.

All estimates should be flagged clearly and quantified — this allows an assurance provider to understand the proportion of your Scope 1 figure that is measured vs estimated, which affects the level of assurance they can provide.

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Ayika tracks fuel data by vehicle, plant item, project, and site, with NGA factor application and source document storage built in. See how fuel reporting works in the platform.