Vehicle Modification Engineering & Certification
Engineering assessment and certification for suspension, chassis and body modifications, bull bars, towing systems and other light vehicle modifications. KME Vehicle Engineering assesses the vehicle, proposed/existing modification and applicable technical requirements, with the certification pathway determined by the modification and registration jurisdiction.
What is vehicle modifications engineering?
KME Vehicle Engineering provides engineering assessment and certification for vehicle modifications including suspension changes, bull bars, chassis and body modifications, towing systems, seating and restraint changes, wheel and tyre modifications, and other bespoke vehicle engineering.
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The applicable technical and certification pathway depends on the vehicle category, modification type and registration jurisdiction. Our role is to assess the proposed modification, identify the evidence, calculations, inspection or testing required, and prepare the applicable certification documentation where the engineering assessment supports the modification.
How do I choose a vehicle modification engineer?
Look for an engineer with experience in the type of modification you are planning, knowledge of the relevant vehicle standards and jurisdiction, and a clear process for assessment, inspection, evidence and certification. KME Vehicle Engineering works with vehicle owners and workshops on modification projects across Australia.
Common modifications we certify
Suspension & GVM related modifications
Engineering assessment of suspension changes and related vehicle mass impacts.
Seating & restraint modifications
Engineering assessment of seating changes, seat installations and occupant restraint modifications.
Wheels, tyres & other complex modifications
Assessment of wheel and tyre changes and other bespoke modifications that require vehicle-specific engineering review.
Towing systems & couplings
Assessment of towbars, couplings and towing-related modifications, including relevant vehicle limits.
Bull bars & frontal protection systems
Engineering review of frontal protection systems against applicable vehicle and modification requirements.
Chassis & body modifications
Assessment of structural changes, body alterations and modification effects on vehicle integrity.
How the engineering process works
01
Assessment
We review the vehicle, proposed modification, current configuration and registration jurisdiction to identify the likely engineering pathway.
02
Engineering
KME assesses the modification against the relevant technical requirements and identifies any calculations, component information, testing or supporting evidence required.
03
Inspection
The completed vehicle is inspected and, where required, measured, weighed or tested to confirm the modification and supporting evidence.
04
Certification
Where the engineering assessment supports the modification, KME prepares the applicable certification documentation for the relevant approval pathway.
Related services
Vehicle modifications by State & Territory - a quick guide
Vehicle modification requirements are not identical across Australia. The applicable technical standards, signatory requirements, inspection process and registration-authority pathway depend on the vehicle, modification and state or territory of registration.
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KME Vehicle Engineering can assess the proposed modification and advise on the engineering pathway, but final acceptance and registration requirements are determined by the relevant jurisdiction.
Northern Territory
Max tyre size increase without engineering
50mm
Max suspension lift without engineering
50mm
Body lift permissible
Yes with engineering
Max roof height increase without engineering
50mm total (tyres+suspension+body lift)
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, no for already registered vehicles
Queensland
Max tyre size increase without engineering
50mm
Max suspension lift without engineering
50mm
Body lift permissible
Yes
Max roof height increase without engineering
75mm total (25mm tyres+50mm suspension)
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, no for already registered vehicles
Western Australia
Max tyre size increase without engineering
50mm above the largest tyre in your model range
Max suspension lift without engineering
50mm
Body lift permissible
Yes with engineering
Max roof height increase without engineering
50mm total (tyres+suspension+body lift)
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, yes possible for already registered vehicles
South Australia
Max tyre size increase without engineering
50mm
Max suspension lift without engineering
50mm
Body lift permissible
Yes with engineering
Max roof height increase without engineering
50mm total (tyres+suspension+body lift)
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, and already registered vehicles
Victoria
Max tyre size increase without engineering
50mm
Max suspension lift without engineering
50mm
Body lift permissible
Yes
Max roof height increase without engineering
75mm total (25mm tyres+50mm suspension)
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, and already registered vehicles
New South Wales
Max tyre size increase without engineering
50mm
Max suspension lift without engineering
50mm
Body lift permissible
Yes with engineering
Max roof height increase without engineering
75mm total (tyres+suspension+body lift)
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, and already registered vehicles
Tasmania
Max tyre size increase without engineering
50mm
Max suspension lift without engineering
50mm
Body lift permissible
Yes
Max roof height increase without engineering
50mm total
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, and already registered vehicles
ACT
Max tyre size increase without engineering
50mm
Max suspension lift without engineering
50mm
Body lift permissible
Yes with engineering
Max roof height increase without engineering
75mm total (tyres+suspension+body lift)
GVM upgrade possible
Yes - pre registered and already registered vehicles
GCM upgrade possible
Yes pre-registered, and already registered vehicles
A Guide to the Vehicle Modification Process Around Australia...
Northern Territory - more details
Vehicle modification approval in the Northern Territory is administered by the Motor Vehicle Registry (MVR), within the Department of Logistics and Infrastructure. Depending on the vehicle and modification, the pathway may involve MVR assessment or inspection, certification by a recognised engineering signatory and, for significant or extensive light-vehicle modifications, Technical Advisory Committee consideration. VSB 14 is the primary technical reference for light vehicles, while VSB 6 applies to heavy vehicles and may also be used for some light-vehicle assessments.
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The NT advises that, in most cases, it will recognise certification from an interstate engineer who is recognised or approved by their home registration authority. Acceptance still depends on the specific vehicle, modification and MVR requirements. Vehicle owners taking an NT-certified vehicle interstate should confirm the receiving jurisdiction’s requirements before relying on the certification.
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Heavy-vehicle modifications in the Northern Territory are administered by the MVR. The NT has not adopted the Heavy Vehicle National Law, although VSB 6 is used as the principal technical standard for assessing heavy-vehicle modifications.
Queensland - more details
Queensland runs its own scheme rather than deferring entirely to VSB14 — modifications are governed by the QCOP (Queensland Code of Practice: Vehicle Modifications), administered by the Department of Transport and Main Roads (TMR).
Modifications fall into four categories: Minor (accessory fitments needing no approval), Basic, Complex, and Specific. Only complex modifications — engine upgrades, suspension upgrades, mass re-rating, gearbox changes, vehicle body modifications, steering and brake replacements — require certification, and that certification must come from an Approved Person, accredited under TMR's Approved Person Scheme based on their industry experience and qualifications.
An important state-specific quirk: modifications performed and certified in another jurisdiction are not automatically recognised in Queensland. If a vehicle was modified and certified interstate, it generally needs to be re-approved by TMR or re-certified by a Queensland-approved person before Queensland registration — this matters for any customer bringing an interstate-modified 4WD into QLD.
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Western Australia - more details
Western Australia uses a tiered Minor, Simple and Complex modification system administered by the Department of Transport and Major Infrastructure (DTMI). VSB 14 may provide relevant technical guidance, but WA also applies its own Vehicle Technical Bulletins, Information Bulletins and approval requirements.
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The required approval pathway depends on the specific vehicle and modification. Owners should confirm any pre-approval, engineering and inspection requirements with DTMI before work begins.
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A vehicle that remains registered in another Australian jurisdiction can generally travel in WA under the ratings and approval recorded in its home jurisdiction. However, transferring the vehicle to WA registration is different: the modification must satisfy WA requirements and be accepted by DTMI. Owners should confirm this before purchasing or transferring an interstate-modified vehicle.
South Australia - more details
South Australian light-vehicle modifications are administered by the Department for Infrastructure and Transport (DIT). Significant modifications may require an application before work begins, a Statement of Requirements, assessment by a recognised Light Vehicle Engineering Signatory and final acceptance by DIT.
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Pre-registration and in-service mass changes follow different approval pathways. Whether a GVM or GCM re-rating is available depends on the specific vehicle, proposed rating, technical evidence and DIT requirements. A GVM or GCM change does not automatically increase the vehicle manufacturer’s braked towing capacity.
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Tyre, suspension and body-height changes must be considered together, including their effect on overall vehicle height, handling and applicable testing requirements. Owners should confirm the required approval and testing pathway before commencing the modification.
New South Wales - more details
NSW runs off VSB14 like most other states, but is also administered through its own certification scheme — the Vehicle Safety Compliance Certification Scheme (VSCCS), run by Transport for NSW. VSCCS licenses individuals (not businesses) to inspect non-standard and modified vehicles and issue compliance certificates electronically; certifiers need a minimum Certificate IV in a relevant discipline, and must carry significant public liability and professional indemnity insurance. A second tier, VSCCS J&P, covers heavy vehicle body-fit and tow coupling/fifth-wheel modifications specifically.
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NSW has also published its own supplementary guidance beyond the national code — a dedicated light vehicle modifications manual covering suspension and ride height — meaning NSW customers may need to satisfy state-specific detail on top of the base VSB14 requirements, not just the national standard alone.
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NSW requirements for tyre, suspension and body-height changes depend on the vehicle, the combination of modifications and the applicable NSW Suspension and Ride Height Manual. Significant modifications must be assessed and certified through the VSCCS pathway; owners should not rely on one general height limit without checking the vehicle-specific requirements.
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GVM and GCM re-ratings are also vehicle- and evidence-specific. A licensed VSCCS certifier should be consulted before work begins to confirm the applicable standards, inspections and registration-update requirements. GVM, GCM and braked towing capacity are separate ratings, and changing one does not automatically increase the others.
ACT - more details
The ACT doesn't run its own named certification scheme like VASS or VSCCS — instead it applies the National Code of Practice (NCOP) and VSB14 directly, with significant or extensive light vehicle modifications requiring certification by a recognised engineering signatory before the vehicle can be re-registered.
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Because the ACT largely defers to the national standard without heavy state-specific amendment, it's generally treated as one of the more straightforward jurisdictions to work with. However, confirm the applicable pathway with KME or Access Canberra rather than assuming the ACT requirements mirror those of NSW or Victoria.
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Victoria - more details
Victoria administers modifications through the Vehicle Assessment Signatory Scheme (VASS), run by Transport Victoria (formerly VicRoads). VASS-approved engineering signatories assess and certify modifications against VSB14. A VASS approval certificate for a light vehicle is only valid for 30 days from issue — the vehicle must be presented for roadworthy inspection and registered within that window, or the certificate lapses. Certificates for modified heavy vehicles don't carry this expiry. Also worth noting: only Victorian residents/entities are eligible to be authorised as a VASS signatory in the state — an interstate engineer can't hold a VASS authorisation.
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Victorian requirements for tyre, suspension and body-height changes depend on the vehicle and the applicable VicRoads guidance or VASS approval pathway. GVM and GCM re-ratings are vehicle- and evidence-specific, so eligibility should be confirmed with an appropriately authorised VASS signatory before work begins. A change to one vehicle rating does not automatically increase the others.
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Worth flagging for VIC customers: the 30-day validity window on light vehicle VASS certificates means timing between certification and registration matters more here than in most other states — a delay in booking the roadworthy/rego appointment can mean redoing the certification.
Tasmania- more details
Tasmania administers vehicle modification certification through the Approved Vehicle Certifier Approved Inspection Station (AVCAIS) scheme. The certifying authority is the Registrar of Motor Vehicles through Transport Services, which is now a division of Building Tasmania.
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An Approved Vehicle Certifier assesses the modification against the applicable vehicle standards, including VSB 14 and Tasmania’s Vehicle Modification Certification Manual. Where the requirements are satisfied, the process may include a modification certificate and modification plate.
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Tyre, suspension, body-height, GVM and GCM requirements depend on the specific vehicle and modification. Owners should confirm the applicable certification, inspection and registration pathway with an Approved Vehicle Certifier before commencing significant work.
Frequently asked questions
What vehicle modifications can KME Vehicle Engineering assess?
Does every vehicle modification need engineering certification?
Can KME Vehicle Engineering help with modifications outside Darwin?
Can KME certify suspension, wheel or tyre modifications?
Can KME help with chassis or body modifications?
What information should I send for a vehicle modification assessment?
Daly was a pleasure to work with and has a wealth of knowledge, which he is happy to share. He is able to explain ADR requirements in simple terms and is more than happy to help customers understand the pathway to certification.
Steve P.
Very professional and efficient service. Daly is very knowledgeable and obliging and a pleasure to deal with.
Duncan T.
I can't complain about getting my GVM upgrade the same day I asked and paid!! Too good to be true. Amazing service.
Jamie L.
Our business is to know the rules
So you don't have to.
