Are Oversized Tyres Legal in South Australia?
Short answer: sometimes—but “oversized” needs to be measured the right way.
In SA, the key question isn’t “what size can I run?”
It’s: how much bigger is your overall diameter vs the tyre placard?
1) The SA rule that decides legality: overall diameter vs tyre placard
SA’s guidance is specific:
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Most vehicles (non-4WD): overall diameter must be no more than 15mm larger than the largest size listed on the tyre placard (and no more than 15mm smaller than the smallest).
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4WD vehicles: an increase in overall diameter of up to 50mm is acceptable.
So if you’re fitting oversized tyres on a 4WD, you generally have more room than a standard passenger car—but you still have a hard limit to respect.
2) The “gotchas” that get oversized tyres defected (even if diameter is OK)
A) Wheels/tyres must not foul anything
SA requires wheels must not foul body/suspension/any vehicle part under any operating conditions.
If your tyre rubs at full lock, on bumps, or under load—expect trouble.
B) Tyres must not stick out beyond bodywork
SA requires the wheels must not project beyond bodywork (viewed from above, straight-ahead).
Big tyres + aggressive offset is the classic combo that fails this.
C) Wheel track change limit (very common with “oversized tyre” builds)
Many “bigger tyre” setups also involve new wheels/offset.
For passenger cars (and derivatives), SA says track must not be increased by more than 26mm beyond manufacturer maximum.
If you’re pushing wheels outward to clear suspension/arms, the track rule becomes the bottleneck quickly.
D) Spacers: mostly not allowed
SA says spacers are not permitted unless originally fitted by the manufacturer.
If your oversized tyres require spacers to “make them fit”, that’s a red flag.
3) Oversized tyres often change ride height — know SA’s 50mm threshold
SA allows ride height increase up to 50mm total (from suspension/body/tyres combined) without a roadworthy inspection. Over 50mm requires prior approval + LVES report + roadworthiness inspection.
If your plan is “bigger tyres + lift kit”, add the numbers—don’t assume.
4) How to choose a legal oversized-tyre setup (simple method)
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Photograph your tyre placard
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Pick the tyre size you want
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Compare overall diameter vs placard:
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Non-4WD: stay within +15mm max
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4WD: stay within +50mm max
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Confirm it won’t:
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rub (full lock + compression)
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stick out beyond guards
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blow out track limits if you’re changing wheels/offset
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require non-OEM spacers
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5) When it’s time to ask for approval (don’t gamble)
If your oversized tyre plan triggers major changes (lift/track/brake clearance/body mods), SA has an official process involving Vehicle Standards, Statements of Requirements, and potentially a Certificate of Exemption after roadworthy inspection.
CTA
Want oversized tyres that are legal, drivable, and won’t rub?
Bring your tyre placard photo (or send it to us) + tell us your vehicle model and the size you want. We’ll help you pick a setup that respects SA’s diameter + track + clearance rules before you spend money.