• Jun 2, 2020 modified: Apr, 23 2026

Tyre Pressure

Updated Apr 2026

One of the most neglected tasks in motoring is checking tyre pressures.

Tyre Pressure is measured in PSI (pounds per square inch) or kPa (kilopascals for metric measurements).

1 kPa is equal to 0.145038 PSI.

It is best to inflated tyres when they are cold to ensure you get the correct reading. It is recommended to inflate your tyres in the morning.

Incorrect Tyre Inflation Pressure

• tyre failure
• rapid/uneven tyre wear
• increased fuel consumption

How accurate are tyre inflation guages?

Is there a difference between the accuracy of a mechanical style inflator guage and an electronic unit with a required pressure preset function?

The RACQ surveyed 59 Brisbane service station sites (2005) with the following findings-:

The electronic units were mostly found ot be more accurate with 94.4% accurate within 5%.

Of the mechanical units only 67.6% were within the 5% range.

Reliable Guages today

A high percentage of service stations now have the electronic inflation systems, these are very accurate with only a few parts that can cause a problem [ Air hose and tyre clip ] - but in general anyone can use these with good results.

Certain industries demand high quality Tyre Accessories - it is recommended to look for a company that sells reliable tyre guages. RLM distributing are Brisbane based and specialise in quality tyre accessories, even supplying mining tools around Australia.

Tyre Pressure Monitoring Systems

Due to legislation in place in the US and Europe, many cars in Australia have a tyre pressure monitoring system. How they detect a tyre issue can vary.

1 Indirect System uses the cars anti-lock ABS sensors to measure different rates of wheel rotation.

2 Direct System uses wireless sensors in each wheel that directly measure tyre pressure and transmit this data to a display unit.

Choice conducted a tyre pressure monitoring comparison where they measured 3 main scores 1. Accuracy, 2. Display, 3. Ease of removal.

The prices of the systems varied from $78 to $399

Mechanical Issues caused by Tyre Pressure

Rolling Resistence refers to the amount of resistance to movement because of tyre friction, contact area with the road, construction of the tyre, and the rubber compounds they are made of.
This and other factors determine the amount of energy (fuel) required to keep the car moving. An under inflated tyre has a larger contact area with the road, causing more Rolling Resistence.

Southport Mechanic Shannon warns customers that the tyres are a large factor in your stopping distances. The problem is that under-inflated tyres deform when under braking pressure, to the point they become less effective. The shock absorbing systems were designed with a certain amount of pressure in mind. An over-inflated tyre will have a bulging centre and also be less effective than ideal inflation levels.

What tyre pressure should you have?

Check your car recommendations. These are usually in the door of the vehicle.

Wheel Balancing

Wheel balancing and tyre pressure are separate issues, but both can cause vibration — just in different ways.

What wheel balancing actually does

Wheel balancing corrects tiny weight differences in the wheel + tyre assembly so it spins evenly at speed.

When a wheel is even slightly heavier on one side, it creates a vibration — usually felt through the steering wheel, seat, or floor once you're above 60–80 km/h.

Balancing fixes that by adding small weights to the rim so the wheel rotates perfectly smoothly.

Why it matters

• Stops steering wheel vibration The classic "shaking at 80 km/h" problem.
• Prevents uneven tyre wear Unbalanced wheels scrub the tyre in patches, shortening tyre life.
• Protects suspension and steering components Constant vibration stresses shocks, struts, bushings, and bearings.
• Improves fuel efficiency Smooth rotation = less rolling resistance.
• Makes the car feel stable and comfortable Especially noticeable on the highway.

When you need wheel balancing

You'll usually need it if you notice:

• Vibration at certain speeds
• A tyre recently replaced or repaired
• You hit a pothole or kerb
• Tyres wearing unevenly
• Steering feels "buzzier" than normal

"Buzzier" may be just a slightly different sensation in the steering wheel.

Most tyre shops recommend balancing every 10,000 km or whenever tyres are rotated.

A wheel alignment works on the suspension angles that contol how the tyre sits on the road.