Two pressure numbers live on and around every car: the placard figure set by the vehicle maker, and the “max” pressure moulded into the tyre sidewall. They are not alternatives. Follow the placard for everyday driving — the sidewall number is a limit, not a target, and running to it will cost you grip, comfort and even wear.
Which tyre pressure should you actually follow?
TL;DR: Follow the vehicle placard pressure — the carmaker’s recommended cold pressure for your car and its standard tyre size. The sidewall “max pressure” is the most the tyre can safely hold, not the pressure you should run. Set pressures cold, adjust up for heavy loads per the placard, and never inflate to the sidewall maximum as a matter of course.
This is one of the most common tyre mix-ups in Australia, and it matters because the two numbers exist for completely different reasons. Getting it right is free, takes two minutes and affects braking, handling, fuel use and how evenly your tyres wear.
What the placard pressure is
The tyre placard is a sticker fitted by the vehicle manufacturer, usually on the driver’s door jamb, inside the fuel flap or in the glovebox. It lists the recommended cold inflation pressures for the car’s standard tyre sizes, often with separate figures for normal and full-load driving, and sometimes different front and rear values. Our full guide to reading your car’s tyre placard shows exactly where to find it and how to read every field.
These figures are the result of the carmaker’s own testing, balancing ride comfort, handling, braking, fuel economy, tyre wear and load capacity for that specific vehicle. That’s the key point: the placard pressure is tuned to your car, not just to the tyre.
What the sidewall maximum is
Moulded into the tyre’s sidewall you’ll find wording like “Max. Press. 350 kPa (51 psi)” — often paired with a maximum load figure. This is the tyre’s limit: the highest cold pressure at which it is designed to carry its maximum rated load safely. Our guide to reading a tyre sidewall decodes every number stamped there.
The sidewall maximum is a ceiling, not a recommendation. It tells you how far you can go, not where you should sit. Inflating every day to that number is like redlining your engine at every set of lights because the tacho says you can.
Placard vs sidewall maximum at a glance
| Placard pressure | Sidewall maximum | |
|---|---|---|
| Set by | Vehicle manufacturer | Tyre manufacturer |
| Means | Recommended cold pressure for your car | Maximum safe cold pressure for the tyre |
| Where | Door jamb / fuel flap / glovebox | Moulded into the tyre sidewall |
| Use it as | Your everyday target | A limit you stay under |
| Tuned to | This vehicle’s ride, load and handling | The tyre’s construction only |
What happens if you inflate to the sidewall maximum?
Running well above the placard — up toward the sidewall max — hardens the ride, shrinks the contact patch and tends to wear the centre of the tread faster. It can also lengthen braking distances because less rubber is meeting the road. This is the over-inflation trade-off covered in what happens if you over-inflate. Running well below placard is the opposite risk — see what happens if you under-inflate — building heat, wearing the edges and, at worst, causing failure. The placard sits in the sweet spot the carmaker chose on purpose.
When you adjust away from the base placard number
Following the placard doesn’t mean one fixed number forever. The placard itself usually gives a higher figure for heavy loads, and there are legitimate reasons to adjust:
- Carrying a full load or towing. Use the placard’s laden/high-load column — see pressures for a fully loaded road trip.
- Off-road on sand or corrugations. Airing down deliberately for flotation or comfort is a temporary technique, covered in our sand-driving pressures guide — you re-inflate to placard before returning to sealed roads.
- Hot vs cold. The placard figure is a cold pressure. Heat and driving raise it — that’s normal and expected, as explained in cold vs hot tyre pressure and how much summer heat raises pressure.
None of these mean chasing the sidewall maximum. They mean using the placard’s own guidance, or a deliberate temporary technique, within the tyre’s limit.
What if you’ve changed tyre or wheel size?
The placard assumes the standard fitment. If you’ve fitted a different size, a higher load-rated tyre or aftermarket wheels, the placard’s numbers may no longer be exactly right, and you should get advice from a tyre professional on the correct pressure for the new setup. Whatever the fitment, your tyres must still meet the car’s placard load rating — running under it is both unsafe and a compliance problem, as our guide to failing the placard load rating explains. The Tyre & Rim Association of Australia standards underpin correct fitment and pressures for the local market, and tyre makers such as Bridgestone Australia give the same advice: follow the placard.
How to set your pressures the right way
Check and set pressures cold — before driving, or after the car has sat for a few hours — because driving warms the tyres and inflates the reading. Set each axle to the placard figure for your load, and don’t forget the spare. If your car has a tyre pressure monitoring system, know that it reports pressure but doesn’t set it for you; see how TPMS works and when it lies. A monthly check is a good habit — more on that in how often to check pressures.
Bottom line: Follow the placard, not the sidewall. The placard pressure is the carmaker’s recommended cold figure tuned to your vehicle and its load; the sidewall maximum is the tyre’s upper limit and should never be your everyday target. Set pressures cold, use the placard’s laden column when heavy, and treat the sidewall number as the fence you stay inside.
Frequently asked questions
Should I inflate my tyres to the pressure on the sidewall?
No. The sidewall figure is the maximum pressure the tyre can safely hold, not the recommended running pressure. Use the placard pressure from your door jamb, fuel flap or glovebox for everyday driving, and keep below the sidewall maximum.
Where do I find the placard pressure?
On a sticker fitted by the vehicle manufacturer — most often on the driver’s side door jamb, sometimes inside the fuel flap or in the glovebox. It lists cold pressures for the standard tyre sizes, usually with a higher figure for heavy loads.
Is it ever OK to run near the sidewall maximum?
Rarely, and not as an everyday setting. Very heavy loads within the placard’s laden guidance may call for higher pressures, but you should stay at the placard-recommended figure for your load rather than chasing the tyre’s maximum. Running at the max hardens the ride and can wear the tread centre and lengthen braking.
Do I set pressures hot or cold?
Cold — before driving or after the car has rested a few hours. Placard figures are cold pressures, and driving warms the air inside, which raises the reading. Checking hot gives a falsely high number, so top up to the cold target, not the hot one.
Pressures and adjustments here are general guidance — always follow your vehicle’s own placard and, if you’ve changed tyre or wheel size, confirm the correct pressure with a tyre professional.
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