Reading a Sidewall

Tyre Brand
The tyre brand is often, but not always, the same as the tyre manufacturer. It serves as a key identifier and can influence perceived quality and performance.

Tyre Tread Pattern
The tread pattern can include:

• A name
• A number
• A combination of letters and numbers
• Or a mix of name + code
  It plays a key role in grip, handling, water dispersion, and noise levels.

Tyre Size and Service Description
These are usually located side by side on the tyre's sidewall.

• Service Description consists of two parts:
  • Load Index: Indicates how much weight the tyre can carry.
  • Speed Rating: Indicates the maximum speed the tyre can safely sustain.

Load Index & Speed Symbol
These markings define the tyre’s load-carrying capacity and top speed.

• Load Index is a number (e.g. 91)
• Speed Symbol is a letter (e.g. V, H, T)
  Together, they ensure your tyres are suitable for your vehicle's specs.

Diameter
The diameter is the size of the wheel (rim) from one side to the other, measured in inches. It must match the tyre to ensure a proper fit.

Radial
If a tyre includes an “R” in its size, it uses radial construction—the most common type.

• Offers flexibility, strength, and a smoother ride.

Aspect Ratio
This number represents the sidewall height as a percentage of the tyre’s width.

• A lower ratio = sportier feel, better handling
• A higher ratio = softer ride, more cushion

Width
The tyre width is the measurement from sidewall to sidewall (in millimetres).

• Affects traction, contact patch, and ride comfort.

Tyre Type
Some tyres include a prefix letter:

• P: Passenger vehicle
• LT: Light truck
  This identifies the vehicle category the tyre is designed for.

Formulas for Reference

• Section Height = (Overall Diameter − Rim Diameter) ÷ 2
• Aspect Ratio (Tyre Profile) = (Section Height ÷ Section Width) × 100

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