Off-Road Accessories

SEMA News—October 2018


By Iain Kelly

Off-Road Accessories:

Australian Laws and Customizing Regulations

Fitting body accessories such as bull, scrub and rock bars are covered by several ADRs, including rules for frontal protection for occupants, headlight clearance and engine cooling.

While Australia is a large country that has roughly the same land mass as the United States, approximately 85% of the population lives within 30 miles of the coast. That leaves huge tracts of sparsely populated land perfect for exploring, which has led to a vibrant and diverse 4x4 and off-road culture Down Under. Along with traditional off-road pursuits, such as trail driving and rock-crawling, Aussies also use modified pickups, 4x4s and utes (pickups) to get to mountain-biking or dirt-biking trails, access camping locations, or as work trucks on farms and in mines.

New vehicles sold in Australia (or privately imported vehicles built after January 1, 1989) must adhere to the Australian Design Rules (ADRs) in effect at the time they were built. Those rules were introduced into legislation by Australia’s federal government in 1969 and have been updated periodically.

ADRs cover emissions equipment on engines (such as smog pumps, cold-start recirculation and oxygen sensors), vehicle noise limits, passive and active safety technologies (such as seat belts, electronic brake-force distribution and traction control) and administering standards for outputs from headlights, accessory lights and taillights. All vehicles registered for use on Australian roads need to adhere to the ADRs that were in place when the vehicles were originally manufactured. Vehicles imported to Australia need to be modified to suit those ADRs by qualified workshops to bring them in line with the minimum standards before they are allowed to be registered in a particular Australian state.

Accessories and ADRs

Fitting body accessories such as bull, scrub and rock bars are covered by several ADRs, including rules for frontal protection for occupants, headlight clearance and engine cooling. All legal aftermarket bars must allow any vehicle frontal protection systems (such as airbags) to remain working as the manufacturer intended and not block light output from the original headlights, and they are rigorously tested to ensure compliance.

Other aftermarket accessories such as roof racks, high-lift jacks, cargo drawers, spare-wheel carriers, rear bumpers, rooftop tents, long-range fuel tanks and lights are all subject to ADRs to be considered legal, and they are tested as such. ADR compliance maintains a minimum safe quality standard for parts being fitted to road-registered 4x4 and off-road vehicles by ensuring that the vehicles adhere to the ADRs they had to comply with when new.

Once the components have been certified as meeting ADRs, they can be fitted to vehicles without going through an extra round of independent certification. That approval applies only to that individual product from that company and doesn’t instantly make any other modifications legal.

Role of State Governments in Regulating Specialty-Equipment Products

State governments control modifications to individual vehicles in Australia. Most state government regulations allow owners to perform basic modifications to their vehicles without any certification, particularly if the owner is fitting upgrades available on other vehicles in that range. This includes fitting optional driving lights or upgrading the wheels and tires within 50% of the original width and no more than 25 mm in height.

More extreme modifications—including engine swaps, adding forced induction, lifting suspension, adding aftermarket brakes, or changes to the vehicle’s body or chassis—require owners to have them approved by qualified certifying engineers under the National Code of Practice for Light Vehicle Construction and Modification (NCOP). This federal legislation is set out in a series of Vehicle Standards Bulletins (VSB), with VSB14 the key document for modified vehicles in Australia. However, each state has amended and modified its legislation to suit its own requirements, and a certifier from one state is not necessarily qualified to approve vehicle modifications in another state.

Suspension and Body Heights

Raising the suspension of a 4x4 is possibly the most popular modification enthusiasts will do to their vehicles, but regulations for what is legal differ from state to state. For example, residents of New South Wales and Victoria can lift their vehicles 75 mm, but the limit is only 50 mm in South Australia. That is because Australia is a federation of six states and two territories, each of which is responsible for its own road laws and licensing. A challenge for car and 4x4 enthusiasts in Australia is that some modifications can be legal in one state and illegal in others.

Modifying a ute or a 4x4 vehicle in Australia often starts with lifting the suspension and body more than 50 mm (2 in.) and fitting larger-diameter wheels and tires. All of those steps require approval from an engineering signatory.

VSB14 allows vehicle owners to raise their vehicles up to 50 mm above the manufactured height without certification and mandates that a certified engineer approve lifts from 50 mm up to a maximum permissible lift of 150 mm (6 in.) over manufactured height. Police in each state can also inspect vehicles on a case-by-case basis, asking to see paperwork from a certifying engineer or even requesting that the vehicle be presented for inspection at a state-run inspection station, in some cases.

Using a certifying engineer means that the owner of the vehicle has an independent specialist check that the vehicle is safe to be used on public roads—not just for the owner but also for other road users. It is a requirement that people check their plans to modify their vehicles with a certifying engineer before altering them and have them fully approved before driving.

Until the engineer has signed off the modifications, a vehicle isn’t legal to drive on public roads. Owners can be stopped by police, fined and made to take the vehicle in for a thorough independent inspection at their expense if they are caught driving without an engineer’s certificate.


Engine Tuning and Performance Parts

The booming popularity of diesel 4x4 utes has seen a dramatic increase in owners having the standard computer tuned on a dyno for improved performance. While ADRs prohibit modifying or removing any emissions-control equipment, many owners are prepared to ignore that prohibition due to the performance gains possible.

Upgrading intercoolers, intakes, exhausts and turbochargers is often the second step for diesel owners—particularly if they are using their utes for towing or heavy-duty off-road driving. Engineering signatories can certify those modifications, provided they are satisfied that the vehicle doesn’t emit more tailpipe emissions than standard.

There has been a trend in the last decade for 4x4 owners to swap in powerful diesels, such as the Duramax V8, or gas V8s, such as Chevrolet’s LS series—sometimes featuring Eaton four-lobe superchargers from Harrop or Magnuson. VSB14 and the NCOP set maximum permissible engine sizes for vehicles (split between naturally aspirated and forced induction) that is worked out from a vehicle’s weight using an algorithm. For example, the maximum engine size for a vehicle weighing more than 1,100 kg. is the vehicle’s weight multiplied by 5.0 (for a naturally aspirated engine) or 3.0 (for an engine using forced induction).

Heavy Chassis Upgrades

While diesel 4x4 utes have exploded in popularity in the last decade, the heart of Australia’s off-road scene is still traditional four-wheel-drive wagons such as the Nissan’s Patrol, Toyota’s Land Cruiser and Prado models, or Land Rover’s Discovery and Defender.

Along with being used off-road, those 4x4s are also often found pulling heavy trailers, so they are often upgraded with helper air bags in the rear springs, heavy-duty towbars, and electronic brake controllers.

ADRs set a maximum legal tow rating for vehicles, listed as both braked and unbraked. However, the rating can be upgraded if the vehicle is signed off by a certifying engineer as having had upgrades made to brakes, suspension and sometimes chassis reinforcement.

Individual states set their own restrictions and requirements for the work needed to certify a tow-rating increase or gross vehicle mass (GVM) upgrade. GVM upgrades are common in off-road and 4x4 culture, as they allow for extra vehicle additions or to pull larger trailers and caravans—a popular pastime in Australia.


SEMA members looking to sell their products in Australia are encouraged to read up on the legislation and understand the common modifications performed to help guide them about where market opportunities lie. There are many opportunities, given Australians’ love of the outdoors and personalizing their cars, trucks and 4x4s.

Join SEMA for the 2019 SEMA Australia Trip, May 9–13

Explore the Australia market of true gearheads and the opportunities for U.S. manufacturers of sought-after products for SUVs, pickups, street performance and racing. The fees for the program include hotel, meals, networking events, briefings, a tour of specialty-equipment shops, and exhibiting at the MotorEx show in a turnkey booth. More information is available at or by contacting SEMA’s Senior Director of International and Government Affairs Linda Spencer at

Australian native Iain Kelly is a freelance writer who has worked on enthusiast car magazines in Australia since 2002, as well as writing and publishing two books: The Cars of Mighty Car Mods and One Perfect Lap: The Wild History of the World Time Attack Challenge. 

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