Know your tyres: Sidewalls explained

Ever wondered what those funny numbers on the side of your tyres mean? We at NamWheels love to help and give you a short explanation of what these digits stand for. 

Example: 225/40 R 18 92 Y

225 = Nominal width of tyre, i.e. how wide the tread area or or road contact patch is in millimetres (here: 225mm)

40 = Aspect ratio, i.e. the ratio between the nominal width and the sidewall height as a percentage (here: 40%)

R = indicates radial construction

18 = Diameter of tyre’s inner rim in inches (also the rim size, here: 18 inches)

92 = Load capacity code, in this casemax. 630kg

Y = Max. Speed Rating, i.e. permissible speed, here 300km/h

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