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Tyre Size Guide

A tyre's size is found by looking at the sequence of letters and numbers written on the tyre sidewall. For the below description we will use the example P185/55 R 15 81H

Width - The tyre width measured in millimetres (185 in the example below).

Aspect Ratio/Profile - The profile is the depth of the tyre sidewall. This measurement is taken from the wheel to the outer circumference of the tyre and is a percentage of your tyre's width. So in this example the profile is 55% of 185mm.

Rim Diameter - The diameter of the wheel rim measured in inches. The example tyre below is 15 inches.


Tyre speed rating and load index - The tyre's load index and speed rating tells you the maximum load capacity and speed that the tyre can be safely operated.

Load index Load in kg per tyre Load index Load in kg per tyre Load index Load in kg per tyre Load index Load in kg per tyre Load index Load in kg per tyre
62 265 75 387 88 560 101 825 114 1180
63 272 76 400 89 580 102 850 115 1215
64 280 77 412 90 600 103 875 116 1250
65 290 78 425 91 615 104 900 117 1285
Speed Symbol J K L M N P Q R S T U H V W Y VR ZR
Speed in kmh 100 110 120 130 140 150 160 170 180 190 200 210 240 270 300 >210 >240
Run Flat Tyres

Run flat tyres provide an extra layer of safety and are designed to be driven on for a certain distance after a tyre loses pressure. After losing tyre pressure, the driver must maintain a steady speed of no greater than 80km/h, for a maximum distance of between 50km - 80km (depending on the tyre brand).

Run Flat tyres may only be fitted onto vehicles specifically manufactured to accommodate Run Flat tyres and these vehicles always have a functional Tyre Pressure Monitoring System (TPMS). Typical vehicle manufacturers that utilise Run Flat tyres are BMW, MINI, Mercedes and Renault. If you currently have Run Flat tyres, you will see the letters 'RFT' written on the sidewall of your tyres.

Please note - the fitting of run flat tyres should be carried out by a specialised fitment centre or Dealer.

Commercial Tyres

Some Commercial, or Light Truck vehicles require Commercial-rated tyres. These tyres will display a "C" after the rim size on the sidewall of your current tyres - e.g. 195R14C. If you require Commercial-rated tyres, please call our Tyre experts on 1300 897 372 and they will help you source the correct tyres for your vehicle.

Mercedes Original Equipment Extended Mobility (MOE) Tyres

Tyres marked with MOE are specially designed for Mercedes vehicles. This provides a limited runflat capability - usually operating in a lesser capacity to Runflat tyres and should only be used on Mercedes vehicles.

Mercedes Benz vehicles equipped with MOE tyres must not be replaced with other tyre variants.

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