This guide provides advice to vehicle owners and modifiers about an alternative method of checking gaseous emission and ensuring compliance after modifying or substituting a vehicle’s engine.

When modifying a heavy vehicle’s engine under Section A of Vehicle Standards Bulletin 6 (VSB6) or a complex modification, an Approved Vehicle Examiner (AVE) is required to ensure that the vehicle as modified continues to comply with the applicable emission requirements.

On this page:

• Testing methods
  • PEMS testing for modifications
• Other requirements
• Resources

For modifications that are:

• carried out to a manufacturer’s specification, such as switching to an alternate engine option or electric control unit (ECU) mapping, the AVE can rely on the OEM’s evidence to confirm the modification meets the required emission standard.
• outside a manufacturer’s specification, physical testing of the modified vehicle is required to verify emission levels.

Testing methods

For vehicles built before Australian Design Rule (ADR) 80, access to simplified testing methods such as DT80 are available and provide a practical and economical avenue to verify a vehicles emissions performance.

Where an engine or emissions related modification requires certification, the only option available is a full ADR emissions test, which involves removing a vehicle’s engine and testing in a controlled laboratory environment. Undertaking this testing is an arduous and expensive process.

PEMS testing for modifications

Portable Emissions Measurements Systems (PEMS) provides a practical and economical alternate to full ADR emission testing for ADR 80 compliant vehicles.

The NHVR permits the use of PEMS to test emissions from modified in-service vehicles, following detailed consideration of the technology in consultation with industry.

This method provides a realistic and efficient testing method to verify emissions, significantly reducing the time and cost associated with laboratory-based testing while ensuring modified vehicles continue to meet the intent of the ADRs.

Heavy vehicle modifications involving Section A of VSB6 and complex modification applications will allow the use of PEMS testing, as an alternate to full ADR 80/.. testing, to verify emissions as part of an engine modification.

PEMS testing for vehicle modifications must follow the Simplified Emissions Test Procedure—Portable Emissions Measurement System.

A PEMS testing facility must be selected in accordance with the above Simplified Emission Test Procedure.

Note: The NHVR does not provide details of eligible PEMS testing facilities.

Other requirements

While this alternative testing procedure is acceptable to the NHVR for certifying a vehicle modified in accordance with VSB6, other governing bodies may have additional requirements which must be met. For example, the conversion of a heavy vehicle to operate on an alternative fuel type, such as natural gas, may be subject to requirements of the relevant state or territory gas authority.

Where this occurs, the modifier must comply with both the requirements of VSB6 and the requirements of the gas authority. Where there may be an inconsistency between the requirements of the NHVR and the other regulatory body, the more stringent requirement is to be applied.

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