How to read weight figures and examples
- Ratings are maximum limits, not measurements of your loaded setup. Confirm the exact variant and approved ratings.
- Measure loaded coupling weight. A percentage or the difference between ATM and GTM ratings does not establish today's coupling weight.
- An added load changes both axle reactions according to its position. A change is not a total axle load; use measured starting axle weights and add each load once.
- Combination mass is unhitched loaded vehicle plus total loaded trailer, or the sum of all coupled axle readings. Count coupling mass once.
- Examples and AI suggestions are planning aids, not verified measurements or compliance clearance. Unknown figures require measurement; active weight-distribution hitches and gooseneck arrangements need their own assessment.
Do I need to tell my insurer about car modifications?
Answer the insurer’s questions accurately and check your policy’s requirements for changes during cover. Before fitting a bullbar, lift kit, canopy, different wheels or a GVM upgrade, ask your insurer how the change affects your policy. Keep its response in writing. A modification does not automatically mean every claim will be refused, and declaring it does not automatically guarantee cover.
This guide helps you prepare the vehicle information for that conversation. ClearPath does not decide insurance cover, recommend an insurance policy or provide engineering certification. Your insurer determines what it will cover under your policy.
What to check before fitting or insuring a modification
As one insurer’s example, AAMI’s modification guidance asks its customers to advise it of planned or fitted accessories and modifications. Its approach is not a promise that another insurer or another policy will treat your vehicle the same way.
Do bullbars and winches affect insurance?
Ask about both acceptance and replacement value. Give your insurer the exact bullbar and winch details rather than saying only that the vehicle has accessories. Check whether they are included in the amount insured and whether any installation documents are needed.
For the vehicle-weight check, record the net extra mass after removed factory parts and use measured axle weights where available. A generic bullbar weight cannot establish your vehicle’s front-axle margin. Insurance acceptance and vehicle-weight suitability are separate questions.
What about lift kits, wheels and tyres?
Give the insurer the actual suspension and tyre changes, with installer records and any relevant engineering or registration documents. Ask whether its cover has conditions for the changed setup or your intended off-road use.
Approval requirements depend on the exact vehicle, combination of changes and registration jurisdiction. A statement from an insurer is not a road-authority approval. Use the ACT and NSW modification preparation guide to organise evidence where those jurisdictions apply; it does not issue approval.
Does a GVM upgrade guarantee insurance cover?
No. Provide the exact upgrade documents and ask the insurer to confirm how the altered vehicle will be treated. Check what the approval actually changes. Do not assume a GVM upgrade also raises GCM, axle ratings, towing capacity or coupling limits.
Keep the engineering documents, changed ratings and registration records together. An engineering approval and an insurer’s acceptance address different matters; neither substitutes for the other. Read what GVM upgrades do and do not change before relying on increased carrying capacity.
Consumer insurance: answer questions with reasonable care
The Insurance Contracts Act distinguishes consumer insurance contracts from other contracts. Section 20B sets a duty for consumer insurance applicants to take reasonable care not to make a misrepresentation. It should not be described as a blanket duty for every consumer to volunteer every material fact under the separate disclosure rules for other contracts.
In practice, answer questions truthfully and carefully, ask for clarification if a question about modifications is unclear, and follow the policy’s notification terms during cover and at renewal. Claim outcomes depend on the policy, facts and applicable law; an undisclosed change is not an automatic answer to every claim. Discuss a specific coverage question with your insurer or a qualified adviser.
Prepare a modification record for your insurer
For touring and towing measurements, use the free caravan weight worksheet. Record limits separately from actual loaded weights and mark missing figures Unknown. You do not need to purchase a ClearPath report to ask your insurer whether a modification is covered.
Where a ClearPath assessment can help
If your separate question is how accessories and modifications affect payload and towing, compare the Complete Vehicle Build Assessment — $149. It provides automated vehicle and setup decision support from supplied figures and stated assumptions. It does not confirm insurance coverage or certify a modification.
For a vehicle-and-caravan weight question, review the Vehicle + Caravan Assessment — $99. View illustrative sample reports before choosing. Gather missing measurements first; payment cannot make unknown figures known.
Sources and content review
Content reviewed 14 October 2026. Original publication date is retained separately.
Insurance Contracts Act 1984 — Federal Register of Legislation: consumer insurance provisions, particularly sections 20A–20B, and the separate rules for other contracts. Refer to the register for the applicable version.
AAMI — car modifications and customising insurance: one insurer’s published example of notification and valuation guidance, not a recommendation or universal policy rule.
ASIC Moneysmart — car insurance: independent information about car-insurance options. Check your own policy documents and insurer’s written response for your vehicle.