This guide provides advice to operators, modifiers and certifiers about the requirements for modifying or installing alternative fuel systems.

Alternative fuel systems may offer significant opportunities for innovation across Australia’s heavy vehicle industry. Exploring and adopting existing or emerging alternative fuel technologies is a key part of the heavy vehicle industry, including environmental impact.

On this page

• Alternative fuels
• Alternative fuel systems
• Modifying an existing fuel system
  • Common modifications
  • Complex modifications
• Applying for a complex modification
• Resources

Transitioning to alternative fuels or adding fuel enhancement and supplement systems can deliver a range of benefits, including environmental such as reduced greenhouse gas emission, reduced pollution emission; energy security and lower operational cost for the vehicle’s operator.

Generally, for heavy vehicles to operate on alternative fuel systems, modifications will be required. These can include, but not limited to, the engine, body, and even the chassis in some cases.

Modifications to a heavy vehicle without proper design and approval can cause significant safety risks to the driver, other road users and public. In addition, they can also cause adverse impacts on infrastructure, the environment and community amenity concerns.

Despite the dangers that unapproved modifications to fuel systems can present, the NHVR, road transport authorities and work health and safety regulators continue to see heavy vehicles operating with these unapproved fuel system modifications.

Note: Installing or modifying these systems requires approval from the NHVR.

Alternative fuels

Energy sources besides diesel and petrol are typically considered alternative fuels. These are typically categorised into groups including, or a combination of:

• electric
• hybrid electric
• hydrogen
• liquefied petroleum gas
• natural gas; and
• alternative fuels such as bio-diesel, ethanol, etc.

Alternative fuel systems

Alternative fuel systems can be used in many ways, including:

• single fuel
• multi-simultaneous fuels
• dual fuel; or
• add on enhancement and supplement systems.

Modifying an existing fuel system

Modification of an existing fuel system to an alternative fuel system can include, but is not limited to:

• add-on fuel enhancement and supplement systems
• full replacement of fuel systems
• changes to original equipment manufacturer (OEM) system to operate on alternative fuels like biodiesel, etc.

A person must not modify a heavy vehicle unless the modification has been approved.

• Common modifications must be approved by an Approved Vehicle Examiner (AVE)
• Complex modifications must be approved by the NHVR.

Common modifications

Vehicle Standards Bulletin 6 (VSB6): National Code of Practice Heavy Vehicle Modifications (VSB6) is the national standard for the most common modifications made to heavy vehicles.

While Modification Code A1 – Engine substitution, allows for conversion of petrol engines to diesel and vice versa, it does not cover the installation or conversion of alternative fuel systems.

Note: This means that the alternative fuel conversion cannot be completed in accordance with VSB6 and approval from the NHVR must be granted for a complex modification.

In some cases, there may be related modifications required as part of the alternative fuel conversion. Where these modifications are carried out in accordance with the relevant sections of VSB6, an AVE may approve the relevant component of the modification.

All related modification approvals should be included with the complex modification approval.

Complex modifications

There is no dedicated modification code for the installation or modification of alternative fuel systems, therefore approval must be granted by the NHVR to carry out the modification.

This includes the use of hydrogen in any of the above-mentioned alternative fuel system and any modifications that change in the vehicle power train to no longer comply with OEM specifications.

Note: Modifying a vehicle to electric/hybrid cannot be approved as a common modification.

Applying for complex modification approval

Applications for complex modifications are completed through NHVR Go. More information can be found at Approval to modify a heavy vehicle.

Applications for a complex modification must include evidence in support of the modification. In addition to a completed engineers report, supporting documents for the installation of alternative fuel systems should include, but are not limited to:

• Outcome of diesel exhaust emissions test, either through
  • a DT80
  • In Service Emission Testing in line with the Simplified Emissions Test Procedure – Portable Emissions Measurement System
  • ADR 80/.. Emission Rates
• UNECE R134, R100 etc
• Gas certificates
• Support from the Department of Climate Change, Energy, the Environment and Water (DCCEEW) Fuel Quality Regulator.

Resources

Chain of Responsibility

The Primary Duty requires Chain of Responsibility parties to ensure, so far as is reasonably practicable, that they carry out their transport activities in a way that ensures public safety when heavy vehicles are used on a road.

Keeping up to date with vehicle standards and implementing them in your fleet is one part of your transport activities.

Complying with the national heavy vehicle safety standards

The operator of a heavy vehicle must ensure that their vehicle complies with the relevant Australian Design Rules (ADRs) and the Heavy Vehicle (Vehicle Standards) National Regulation. Using or permitting another person to use a defective heavy vehicle on a road is an offence.

A defective heavy vehicle is a vehicle that:

• does not comply with the heavy vehicle safety standards; or
• has a part that does not perform its intended function; or
• has deteriorated to an extent that it cannot be reasonably relied on to perform its intended function.

More information can be found at Heavy vehicle defects.

NHVR support

If you have questions or require further information, please contact the Vehicle Standards team.

Changes and updates