Lowering the car has traditionally been an easy way to help improve its handling, with a lower center of gravity helping the vehicle's road holding ability.
- Lowering the car is legal, but there are limits
- If your vehicle is too low, it could be defective or impounded.
- Fines may apply for driving an unroadworthy vehicle.
But there are different laws across the country that govern what you can and cannot do when you plan to lower your vehicle.
This story won't go into every detail for every state and territory, so if you plan to lower your vehicle but aren't sure what the local rules are, be sure to check the relevant documentation for your jurisdiction and/or consult a mechanic or certifier. of vehicles to determine what you can and cannot do to achieve the ideal result.
The best known measure when lowering the vehicle is 100 mm. That is what the Australian Design Rules (ADR 43) establish as an acceptable level of ground clearance.
Specifically ““any point on the width of the vehicle that is within one meter in front and behind any axle.” There must be a clearance of 100 mm between the vehicle and a flat surface. However, wheels and fenders do not count towards this measurement.
police in queensland They are advanced in their approach to this measurement. The Queensland Police Service has a measuring wheel that can determine if a car has less than 100mm of clearance and suggests that if you're unsure if your car is too low, “a simple block of wood cut to 100 mm and placed under your vehicle at home would be an easy alternative.”
Further reading should include the National Code of Practice for the Construction and Modification of Light Vehicles (NCOP), published by the Australian Government Department of Infrastructure, Transport, Regional Development, Communications and the Arts.
That document incorporates sets of living and changeable guidelines for vehicle modifications.
According to the Department's site: “The National Code of Practice for the Construction and Modification of Light Vehicles (VSB 14) has been prepared by members of the Australian Motor Vehicle Certification Board Working Group in consultation with industry, users, government agencies and individuals with an interest in modifying light vehicles and/or building individually constructed light vehicles (ICVs).”
Citing VSB 14, Section LS – Suspension and Steering – it states that “basic modifications not requiring certification” include lowering a vehicle, provided that the “total change in vehicle height resulting from all modifications made does not exceed 50 mm “.
Additionally, the following is fine and does not need certification: “Lowering and raising suspensions (no more than one-third of the original suspension travel, as long as the original vehicle height is not increased or decreased by more than 50 mm).”
So why do people lower their cars? It could be to improve the driving experience, improve the appearance of the car, or both. Some people will also claim that a lower car will offer better fuel economy and efficiency, and while there may be some merit to that, you're not going to blow up a police officer if his exhaust system was emitting sparks on the road. .
Lowered suspension generally offers a harsher or firmer ride characteristic, meaning a stiffer experience for those inside the car, but the upside is more assertive handling and greater cornering dynamics.
Victoria's The vehicle standards information sums it up succinctly: “Lowering or raising the ride height of a vehicle by altering its suspension will alter the amount of suspension travel. For example, lowering a vehicle by installing shorter springs will reduce the amount of suspension travel available in the “bump” or up direction. Similarly, raising a vehicle by installing longer springs will reduce the amount of travel available in the downward or “droop” direction.
It's worth noting that if you have a new car or a vehicle that is still under the new car warranty, you should check the fine print in the paperwork, as a modification, such as a lowered suspension, may void warranty coverage. .
Unsurprisingly, sportier cars are more likely to be lowered, but there are modification scenes where people lower their sport utility vehicles or SUVs to obtain a certain stance, and they could do so by installing lowered springs (which are lowering springs). shorter suspension than lowering the ride height), or replacing the suspension entirely with a different type of setup, either coilover suspension or perhaps airbag suspension setups.
There are other ways to do it. Some vehicles may be equipped with lowering blocks and some modifiers with leaf spring-equipped vehicles may choose to reduce the number of leaf springs in the suspension. However, a ute with three leaf springs instead of five would be less capable of carrying a heavy load, but would appear lower if there was a load in the tray.
Other unconventional ways to lower a car include “cutting” the car's suspension springs, but this is dangerous and defect-worthy.
In fact, there are rules about how low your car can go.
Some jurisdictions state that you are legally allowed to adjust your vehicle's ride height by +/-50 mm (1.9685 inches), which might explain why the lowered height most marketed for car springs when you buy them is a of “two spring lowered in inches”.
Another example, in New south Wales The Light Vehicle Modifications guidelines state that it is legal to adjust a vehicle's ride height, as long as you do so within certain parameters: “Altering the vehicle's ride height by more than one-third of the manufacturer's suspension travel in the direction of ride height change”. .”
The guidelines further state that certification (signed by a person accredited as an authorized certifier in the TfNSW Vehicle Safety and Compliance Certification Scheme) is not required. [VSCCS]), for the next:
- Suspension modification with components or parts that meet or exceed the original vehicle manufacturer's specifications.
- Installing sway bars, shocks, springs, struts, or upgraded manufacturer options for that particular year and model
However, there are some more important jobs that will require approval from a certifier, including:
- Conversion from coil springs to leaf springs
- Any modification to the suspension setup.
- Mount a suspension of another design, for example of another brand and model (for example, from coil springs to leaf springs)
- Manufacturing suspension mounting points.
There is a common standard across the country when it comes to legal ride height: that is, a minimum running clearance of 100mm is required. If you have a lowered car that drives but only has 90mm of clearance, you can expect to be abandoned and/or fined.
For airbag suspension, Victory states that it is “acceptable” provided it has been certified (VASS Certificate of Approval), and provided that: “the ride height of an individual wheel or axle cannot be modified while the vehicle is in motion; at least two-thirds of the original suspension travel in any direction is retained at all selectable ride heights while the vehicle is moving; The original vehicle attitude is maintained at all selectable ride heights while the vehicle is in motion.”
Cars with airbags must also comply with the 100mm road clearance while moving and “when parked”.
As mentioned, there are more specific details on how to narrow down the rules and laws depending on where you live. If you intend to lower your car, make sure you do it legally and responsibly.
It is not intended to be legal advice. Check with the relevant highways authority in your state or territory.