Tyre Terminology 

Tyre terminology can often be confusing at times. Refer to this glossary of general terms to make an informed decision about your purchase.

When referring to the tyre sidewall (we will speak more about this soon) there will be sequence of numbers, letters and symbols that may be confusing. This handy guide will help you figure out what all these ambiguous things mean.

Tread

Tread is the part of rubber on your tyre that makes direct contact with the road. As tyres are used, the tread is worn off. We always refer to tread or tread wear when looking at replacing your tyres.

Bead

Tyre bead is the edge of the tyre that sits on the wheel holding it together.

Sidewall

The sidewall is the vertical space of your tyre with a smooth edge. The sidewall contains markings such as tyre size.

Aspect Ratio

You can find your tyres aspect ratio on your tyres sidewall. Aspect ratio means the tyre height as a percentage of the width.

Load Index

Load index is located on your tyres sidewall and informs you on the load carrying capacity of your tyre.

Speed Rating

Speed rating will tell you the maximum speed your tyre can legally travel at.

Tyre Type

Tyre type can mean a number of different things from the construction to type of tyre your vehicle requires such as a passenger tyre.

Alignment

A wheel alignment measures the angle of your wheels in reference to each other and the vehicle. When measured by your tyre specialist, the vehicles suspension can be altered to the ideal alignment

Balance

Balancing refers to distributing the weight of your tyres and wheels equally around the vehicle.

Overinflation

Overinflation occurs when your tyres surpass the recommended PSI. There are very few circumstances in which you should over-inflate your tyres.

Underinflation

Underinflation is quite common when a regular tyre check, monitoring the PSI is missed. We recommend checking your PSI every month to ensure tyres are properly inflated. Certain activities may permit under-inflated tyres such as driving off-road. Always refer to your vehicle manufacture for guidance on the appropriate inflation.

Rotation

Tyre rotation looks at minimising uneven tread wear and prolonging the life of your tyres. A rotation involves moving your tyres around the vehicle.

Tread Wear Indicators

Tread wear indicators are exactly that. They are little bits of rubber that indicate when your tyre should be replaced spread evenly throughout the grooves of your tyre.

All Terrain

All terrain are 4WD or SUV tyres that allow your car to travel on all surfaces including but not limited to: rock, gravel, sand, bitumen and snow.

Highway Terrain

Highway terrain tyres are 4WD or SUV tyres that are primarily made for highway use.

Mud Terrain

Mud Terrain tyres or Muddies are made for extreme off-road driving.

Run-Flat

Run-flat tyres are designed to endure a puncture at a reduced speed and limited distance. This means you don’t need to call a tow truck or change your tyre immediately when punctured.

Part Worn

Part worn tyres are used tyres.

High Performance

High performance tyres deliver exactly that, performance.

All Season

All season tyres are most commonly used among motorists. They provide good handling and braking in hot and cold weather.

Summer Tyres

Summer tyres are designed to perform in a hotter climate.

Winter Tyres

Winter tyres are designed to perform in a colder climate.

Energy Saving Tyres

Energy saving tyres or fuel-efficient tyres have low rolling resistance.

Carcass

Carcass or tyre carcass refers to the framework of the tyre.

PSI

Tyre air pressure is measured as pounds per square inch. The recommend PSI for most vehicles is between 30 and 35 PSI. However, this can vary depending on your vehicle and your vehicles activities.

Rolling Resistance

Rolling resistance is the outside factors that work against your vehicle moving forward. Tyre rolling resistance is the energy or power behind a tyre over a defined distance. A low rolling resistance tyre is generally more fuel-efficient than a conventional tyre.

Speed Rating

Speed ratings are cited in kilometres per hour and converted to miles per hour. It tells us the maximum speed a tyre or vehicle can perform at.

Tyre Placard

Your tyre placard could be located in a number of spots including the glove box, drivers door and inside the fuel cap. You can easily refer to the details in your owners manual. Your tyre placard informs on correct tyre use for your vehicle such as tyre size and inflation pressure. This information can also be found on the sidewall of your tyres.

Traction

Traction refers to your tyres grip on the roads surface. This is something to look for when purchasing tyres particularly if you drive around in wet weather or on dangerous roads. Tread design, compound and tyre construction all contribute to traction.

Valve

The valve is directly located on the inner tube of a tyre and is where you can release or add air to your tyres.

Retreading

Retreading refers to the remanufacturing process of replacing the tread on old worn out tyres to give them a second life.

Rim

Although we may use rim and wheel interchangeably, the rim is actually the outer edge of the wheel holding the tyre and wheel together.

Slick Tyres

Slick tyres or racing tyres have minimal tread and a smooth surface. They are primarily used for racing to generate more speed. Slick tyres are only used for competition and are illegal on our roads.

Tyre Ageing

Your tyres may look brand new but are they safe if they are old? Tyre ageing refers to your tyres deteriorating over time. Tyre ageing is an issue of rubber exposure to oxygen. As the rubber dries out over time it will become stiffer which will lead to cracking. At the bare minimum tyres should be replaced every 10 years. However, should be checked by a tyre fitter annually once they reach the 5 year mark. You can check the age of your tyre by referring to the tyre sidewall. The marking will follow after the letters DOT with the following sequence outlining the week and year the tyre was made. For example, if your tyre was made on the second week of 2021 you will see the numbers 0221.