Lowering your vehicle is traditionally an easy way to help improve handling, with a lowered center of gravity helping to aid traction.
- Lowering your car is legal, but limited
- If your vehicle is too low, it may be deported or impounded
- Can be fined when driving a vehicle that is not eligible to participate in traffic
However, there are different laws around the country that dictate what you can and cannot do when you plan to lower your vehicle.
This story won’t cover every state and territory in minute detail, so if you’re going to lower your vehicle but aren’t sure what the local rules are, be sure to consult the documentation. relevant for your jurisdiction and/or consult your mechanic or vehicle certifier to see what you can and cannot do to achieve ideal results.
The famous measurement when lowering the car is 100mm. That’s what the Australian Design Code (ADR 43) states as an acceptable level of clearance.
Special “any point on the width of the vehicle within one meter forward and aft of any axis.” the distance between the vehicle and the flat surface should be 100 mm. However, wheels and fenders are not counted for this measurement.
Queensland The police are working towards their approach to this measurement. They have a measuring wheel that can determine if a car has less than 100mm of ground clearance, and suggest that if you’re not sure if your car is too low, “a simple block of wood is cut into 100mm and running underneath your car at home would be a simple alternative.”
Further reading should include the National Code of Practice for Light Vehicle Building and Modification (NCOP), published by the Australian Government’s Department of Infrastructure, Transport and Vehicles. That document incorporates sets of live, changeable instructions for modifying the vehicle.
According to the department’s website: “The National Code of Practice for Light Vehicle Building and Modification (VSB 14) has been prepared by members of the Australian Motor Vehicle Certification Board Working Group in consultation with the Australian Motor Vehicle Certification Board. industry, user groups, government agencies and individuals with an interest in light vehicle modification and/or individually built light vehicle (ICV) construction.”
Citing VSB 14, Part LS – Suspension and Steering – it states that “fundamental modifications that do not require certification” include lowering the vehicle, provided that “the total change in height of the vehicle due to all modifications made, does not exceed 50mm.”
In addition, the following is also acceptable and does not require certification: “Lowering and raising the suspension (not more than one-third of the initial suspension stroke provided that the initial vehicle height does not increase or decrease by more than 50 mm).”
So why do people lower the car? It could be to improve the driving experience, to improve the look of the vehicle, or both. Some would also argue that a lower car would offer better fuel economy and efficiency, and while that may have some merit, it won’t fly with the police if your exhaust system sparks along the way.
Lowered suspension often results in stiffer or more confident handling, meaning a more rigid experience for occupants, but the upside is more assertive steering and dynamics. improved in corners.
by Victoria The Vehicle Standards Information succinctly summarizes: “Lowering or raising the vehicle’s travel height by altering the suspension changes the suspension travel distance. For example, lowering the vehicle by fitting shorter springs reduces the amount of available suspension travel in the ‘collision’ or upward direction. Likewise, lifting a vehicle by mounting longer springs reduces the amount of travel available in the downward or ‘down’ direction.
It’s worth noting that if you have a brand new car or one that’s still under the new car warranty, you should check the fine print in the document, for an amendment such as Lowering the suspension may void your warranty. .
As you’d expect, sportier cars are more likely to be lowered, but there are modified scenes where people will lower their ute or SUV for a certain pose and they can do that by installing a lowering spring (which is a shorter shock absorber spring that reduces ride height), or completely replacing the suspension with a different type of setup – be it a coil suspension or maybe the airbag suspension setup.
There are other ways to do that. Some vehicles can be equipped with a lowering block, and some modifications with vehicles equipped with leaf springs may choose to reduce the number of leaves in the suspension. However, a ute with three leaf springs instead of five will be less capable of carrying heavy loads, but will look lower if there is a heavy object in the tray.
Other ways to lower a car include ‘cutting’ the car’s suspension springs – but that’s both dangerous and flawed.
Indeed, there are rules around how low you can make your car.
Some jurisdictions state that you are legally allowed to adjust the ride height of your vehicle by +/-50 mm (1.9685 inches), which may explain why lower heights are sold in high numbers. The best for car springs when you buy them are “two-inch lowering springs”.
Another example, in NSW The Light Vehicle Modifications guidelines state that it’s legal to adjust your vehicle’s ride height, as long as you do it within certain parameters: “Change the ride height by more than a third of the system manufacturer’s suspension moves in the direction of the variable ride height.”
The instructions further state that you do not require certification (signed by someone recognized as a licensed certifier on the TfNSW Vehicle Safety and Compliance Certification Program). [VSCCS]), for the following:
- Suspension modification with components or parts that meet or exceed the original vehicle manufacturer’s specifications
- Fit upgraded coils, shock absorbers, springs, struts, or manufacturer options for that year’s specific make and model
However, there are some larger jobs that will require a validator to sign off, including:
- Conversion from coil springs to leaf springs
- Any modifications to the suspension configuration
- Mounting a suspension of a different design, e.g. from a different make and model (e.g. from coil springs to leaf springs)
- Crafting suspension points
There is a general rule across the country when it comes to legal ride heights – meaning a minimum ground clearance of 100mm is required. If you have a vehicle that is lowered to drive but has only 90 mm of ground clearance, you may be subject to fines and/or fines.
For the airbag suspension system, Victoria declares that it is “acceptable” as long as it has been certified (VASS Certificate of Approval) and as long as: “it is not possible to change the stroke height of an individual wheel or axle when the vehicle is in in motion; at least two-thirds of the initial suspension travel in either direction is retained at all selectable ride heights while the vehicle is in motion; vehicle initial state is maintained at all selectable ride heights while the vehicle is in motion”.
Cars with airbags must also meet a ground clearance of 100 mm when moving, “and when parked”.
As mentioned, there are more specifics around lowering the rules and regulations depending on where you live. If you intend to lower your vehicle, make sure you do it legally and responsibly.
Not intended as legal advice. Check with the relevant road authority in your state or territory.
