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Law changes to make legal suspension lifts and lowers easier

Did you know lifting or lowering your suspension was probably illegal? That’s now changed, thanks to the AAAA.

THERE ARE SO MANY versions of what’s a legal modification. Ask any ten people in the trade what sort of lift or larger tyres you can fit to your 4×4 and you’ll get 10 different answers; “50mm lift is ok”, “33 inch tyres are fine” and so on. Yet the simple fact is that the current laws are written down by each state’s road authority and easily available on their websites; for example in the case of Victoria it’s all available here.  Unfortunately, as usual, each state has its own laws for the same thing and they’re all slightly different.

The good news is that there is a push for national standardisation:

The National Code of Practice for Light Vehicle Construction and Modification [described in Vehicle Standards Bulletin (VSB) 14] has been prepared by members of the Australian Motor Vehicle Certification Board Working Party in consultation with industry, user groups, government agencies and individuals with an interest in modifying light vehicles and/or building individually constructed light vehicles (ICVs).

Source: https://infrastructure.gov.au/roads/vehicle_regulation/bulletin/vsb_ncop.aspx

The idea behind a national standard for vehicle modifications is great, no argument. The implementation of NCOP and its adoption by the states (NCOP’s standards must be made law in each state) is another discussion entirely. 

One of the items covered in the NCOP was what sort of suspension lift or lower you could make to a car without an engineer’s certificate. In the case of a 4WD (not softroader) the answer was 75mm – combined tyres and suspension. That would typically mean a 50mm suspension lift and a 50mm tyre diameter increase (which gives a 25mm lift).  

However, there was this within VSB 14 that describes the NCOP standards (author highlights):


In simple terms, that meant that you could not change your ESC-equipped vehicle – suspension lift, tyres or pretty much anything else – unless you proved that the electronic stability control system (ESC is explained fully here) was not affected, or if it was, then it was modified to suit. So, tens of thousands of ESC-equipped vehicles with aftermarket suspension were illegal. Mostly, people didn’t know about the the issue or just ignored it, including some of the manufacturers.

Testing for a compliance was a big problem, because such testing is very difficult and well beyond what the average owner can afford, and even beyond the resources of many aftermarket companies. But that’s why the AAAA exists – the Australian Automotive Aftermarket Association, who counts amongst their members most, if not all of the major aftermarket companies.

The AAAA decided to see what effect a suspension lift or lower had on modern vehicles with ESC, and in consultation with the regulators tested the following vehicles, both with standard and with modified suspension:

  • 2014 Toyota LC200 +50mm lift
  • 2015 Jeep Wrangler +50mm lift
  • 2015 Chevrolet SS (Commodore) -50mm lower
  • 2013 Toyota Camry -50mm lower
  • Ford PX Ranger +50mm lift

The vehicles were selected to be generally representative of the current market, although you don’t often see Camrys with modified suspension, let alone a 50mm drop.

The AAAA said the aftermarket suspension was from a “range of Australian manufacturers”, and that “internationally recognised test procedures and testing facilities ensured complete transparency”.  The tests were the same ones “used by all vehicle manufacturers and major components suppliers from around the world to simulate vehicle dynamics for the development of new chassis components [and other vehicle systems]”. All up, the testing cost around AUD $250,000 and it was done in Australia and the USA.

2015 Jeep Wrangler used for ESC testing with test equipment fitted.

The results were presented to Australian regulators and showed the test vehicles met Australian Design Rule (ADR) 35 for ESC operation. And as a result, the VSB 14 has been amended (author highlights):


This means that you may now raise or lower your ESC-equipped vehicle, in line with VSB 14, and not need an engineer’s certificate, or worry about ESC operation. There is no need to attempt to modify the ESC system.

The AAAA said that “In some extreme instances the modified vehicles were actually more compliant with ADR 35 requirements than the base vehicles. As expected, the ESC systems on the raised vehicles engaged slightly earlier or more often and used slightly more brake pressure than the base models – due to their higher centre of gravity.”  It’s not clear how a vehicle can be “more compliant”, and earlier activation of ESC or needing to use more brake pressure is not necessarily good. Nevertheless, a pass is a pass.

The text about “in line with VSB 14” is bold so nobody thinks they can do whatever they please; VSB 14 is quite specific about what type of vehicles can be lifted and how, and for example when lowering a vehicle there must be at least a third of the original suspension travel to the bumpstop when unladen. The 50mm figure should be considered a maximum if the regulations (and good engineering principles) permit it. In short, there’s no excuse for not knowing the law or creating unroadworthy vehicles. The more poorly modified wrecks on the road, the harder it’ll be to get laws changed so the good guys can do it right.

There is also a push to standardise vehicle and road regulations across Australia, which will mean the industry can get on with the business of adding value rather than spending time wading through red tape. Senator Ricky Muir is hard at work on just this issue and pointed us to this link on the Future of Australia’s Automotive Industry (read section 5.20).


Lowered Subaru BRZ.


Many Australians need aftermarket suspension for work and recreation – one example is that very few 4X4s are built with suspension suitable for the rigours of outback travel. The aftermarket industry has long met this need, and indeed Australia is known as a world leader in offroad accessories in general, and suspension in particular.

There has been a quiet but long-running debate in the industry about what to do with vehicles that have electronic stability control. Nobody doubts the life-saving potential of the technology, and we should all be proud that Australia led the world in mandating it on new cars. However, the road authorities didn’t investigate the situation and come up with a decision based on solid test results as a result of a transparent process with all involved.  Instead, they side-stepped their responsibility to provide a fair and standard means of regulating roadworthiness by asking for difficult tests.

There were also quite a few naysayers in certain quarters who were certain that any changes to vehicles would mean the electronic safety systems could no longer function as designed.

Now the AAAA with its many members has stepped up and proven that modern vehicles can indeed be lightly modified and still function as their makers intended. This is partly due to good engineering on the part of the aftermarket – not pushing limits, and using their extensive experience to design compatible accessories – but also good engineering on the part of the carmakers. Modern vehicles handle very well, and are equipped with electronic systems that are closed-loop so they can adapt to unusual situations. Improvements in technology help too – older ESC systems were harsh and poorly calibrated, but today’s systems very gradually intervene and are far more progressive.

Hopefully this process will be the start of more collaboration in the automotive industry, working towards an environment where everyone involved can spend more time on building vehicles and less time worrying about red tape.

NOTE: this post is not a complete discussion of the technicalities involved in modifying a vehicle. Read the regulations at the links supplied for details.

This regulation change also only applies to suspension lifts and lowers, not tyre diameter changes. It is also not valid in your state until your state’s laws have been modified to follow the latest NCOP documentation.


Robot steerer used for ESC testing. More reliable than a human driver.

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8 years ago

I understand that not many 4wd ifs fullfill the requirements of retaining 2/3 rds of front end drop when raised 50mm. Hence many current suspension lifts hover around the 35mm mark?

For arguments sake if a vehicle has 10inches (production class off road racing, few have this much) of suspension travel and the vehicle sits static with equal comp/rebound if you raise the vehicle 2inches (ie 2/5 > 1/3?) Your in breach aren’t you?

Were some of those ifs vehicles tested by aaaa in breach of other aspects with 2inch lifts?

Robert Pepper
8 years ago
Reply to  trackdaze

Yes often IFS (independent front suspension vehicles) cannot be lifted 50mm as insufficient downtravel is left. Live-axled vehicles tend not to have this problem. I do not know exactly what was tested; have requested more details and am awaiting the AAAA’s response.

8 years ago
Reply to  Robert Pepper

Its good to see sanity has prevailed after cubic $ have been expended.

No prizes are given for guessing major contributors to the aaaa. If any are listed on the asx im guessing they are up!

Maybe leave sleeping dogs lie.

8 years ago

This has been on the books for 15-20 years – you think this is news??

Robert Pepper
8 years ago
Reply to  Birdman

I don’t think we’re on the same page, Birdman. First, ESC hasn’t been mainstream for anything like 15-20 years. NCOP is much newer, and this recent change to permit suspension changes is only very recent with a notification last week. If you mean the concept of modifying vehicles, well that dates back to probably half an hour after the first car was produced.

Andrew Riles
Andrew Riles
8 years ago

This is one area the states shouldn’t have a say IMO….make NCOP truly national and don’t allow it to be modified by state transport authorities….

7 years ago

Any one know what a jeep wrangler jk would be legally allowed to be raised to in nsw?

7 years ago
Reply to  matt

Hi Matt, not off the top of my head, no. But we can look into it for you. – Isaac

Jenn Nguyen
Jenn Nguyen
6 years ago

HI Isaac. I would also love to know. I read that since november 2016 apparently the legal limit for 4×4’s lift was raised to 75mm is this correct? Also keen to know if one could do a 2″ lift and 33″ tyres and be legal in NSW ?? Or what is the max combination ?

Robert Pepper

Robert Pepper