What this check covers
Selected Queensland wheel, tyre and fitment requirements for the supported light-vehicle scope. Use a combined check when tyre, suspension and body-height changes interact. Whole-vehicle compliance and individual approval conditions need separate assessment.
What you need
- Australian-market manufacturer references and the separately evidenced placard-width floor.
- Documented vehicle category, actual tyre markings and sourced diameter evidence.
- Individual wheel-load, paired load/speed-rating and wheel-fitment records.
Understand the requirements
Use the correct diameter evidence
The September 2025 TMR tyre-diameter instruction requires Australian-market manufacturer references. Use the TRA Design New Tyre Overall Diameter for the correct tread type, or the applicable UN R30/R54 calculation or annex table. Maximum Grown diameter and an ordinary nominal size calculation do not establish the sourced diameter result.
Confirm the actual category and fitment
The February 2026 Minor modifications instruction allows up to 15 mm increase or 26 mm decrease for passenger cars, passenger derivatives and soft-roaders other than MC category. MC, NA and NB1 vehicles within the light-vehicle scope have a 50 mm increase and 26 mm decrease allowance. Confirm the category from vehicle evidence; an AWD label or model name is insufficient.
The width check covers the explicit 1.3 multiplier for established car/car-derivative scope and 1.5 multiplier for MC vehicles with beam axles front and rear. MB needs separate body-class evidence; its ADR code alone does not establish a car body. Non-car MB dimensional rules and other maximum-width cases require review. The minimum width is recorded separately from the narrowest optional tyre indicated on the manufacturer tyre placard; diameter options from a manual or specification do not replace this floor. Mixed tyre sizes, omitted-profile/flotation sizes, special approvals and dual-wheel conversions require separate review. Declare suspension and body changes in the combined assessment. Changed axles or steering require review of the actual configuration.
Document load and speed requirements
Enter the original manufacturer minimum load index for each axle, the lowest fitted single-fitment index per axle, and supported individual wheel loads covering the maximum intended lawful loaded condition. Do not assume equal wheel loads from GVM or axle totals. On an NA light goods vehicle originally fitted with LT tyres, replacement passenger tyres use the highest individual wheel load multiplied by 1.10. NB1 applicability requires review. A complete load result requires paired service-description evidence that all four tyres use the entered speed category. Mixed or unknown speed categories need separate load review, even when all tyre sizes match. Retain tyre-manufacturer evidence that indexed capacity applies at the proposed cold pressure and applicable service conditions. Passenger V/W/Y capacity limits use the vehicle speed capability; intended road speed cannot replace that basis. The assessment does not calculate load/pressure or speed adjustments.
For normal tyres on vehicles built after 1972, the speed check uses the lower of documented vehicle top speed and the QLD class threshold: 140 km/h for off-road passenger vehicles, 180 km/h for cars/car derivatives, or 120 km/h for other motor vehicles. An ADR code alone does not establish every body/speed-class condition. A documented non-car MB body can use an evidenced other-motor speed class while its dimensional rules remain for review. An unknown top speed can still allow a tyre at or above the class threshold; a lower rating requires evidence or review. Road speed limits do not establish vehicle top speed. Earlier manufacture dates, retreads, temporary/limited-use tyres and ambiguous rating markings need separate review.
Record wheel fitment evidence
Record the original standard track, maximum manufacturer track and measured fitted track for each axle. The assessment checks the selected 25 mm car or car-derivative allowance and 50 mm MC or goods-vehicle allowance where that scope is established. A wheel-offset figure alone does not establish the fitted track. Track must not fall below the original standard, and the increase allowance is measured from the manufacturer maximum. For a diagonally split brake system, original front track/offset or an applicable manufacturer optional-rim specification needs separate evidence. Replacement axles and previous approvals require separate review.
Document wheel load capacity and the actual required loaded capacity for each axle, tyre-to-rim compatibility, wheel attachment, coverage, clearance through steering and suspension travel, condition and speedometer accuracy. Aftermarket spacers and adaptors are not supported by the basic pathway; original manufacturer equipment needs supporting evidence. Distinguish a hub-centre adaptor ring from a spacer that moves the wheel outward.
Read every selected result
Missing load, speed or fitment evidence produces a review result even when dimensions are within limits. A supported rating deficit is recorded separately from unresolved evidence. Previously saved assessments keep their original information and results. Run a new check to assess any changes. A new assessment requires the separately evidenced placard-width floor, paired rating confirmation and any MB body-class evidence.
Certification findings apply only to the selected pathways and established evidence. Keep your placard, manufacturer specifications, exact tyre markings and inspection evidence with the dated record. A result outside a basic allowance does not establish that certification is available or sufficient.
Worked example
The largest-diameter tyre need not be the widest
Keep the relevant manufacturer diameter options and placard-width references separately. One optional size cannot establish both comparison baselines unless the evidence supports both.