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Basic Tyre Knowledge

Basic Tyre Knowledge

How to Read Tire Size

Nominal section width (mm)

This refers to the width of the tire excluding design and lettering on the sidewall, etc. *Does not include rim guard.

Aspect ratio (series,%)

This figure indicates the ratio of a tire’s heigh.

Aspect ratio(%)= Tire height÷tire width×100

Construction code

“R” stands for radial structure.

Nominal rim diameter (inches)

Refers to the diameter of the wheel rim suitable for the tire. The term “tire’s inner diameter” is also used.

Load Index (LI)

An index expressing the maximum load permitted for a tire under established conditions.

Speed symbol

This indicates the maximum permissible speed in symbols under established conditions.

Speed category (ZR: over240km/h)

Nominal outside diameter (inches)

Nominal section width (inches)

Load Index: Single/Dual

C: Commercial vehicle

Complies with ETRTO(European tire regulations).

P: Passenger car tire

Complies with TRA(North American tire regulations).

LT: Light Truck

Complies with JATMA(Japanese tire regulations) or TRA(North American tire regulations).

Speed symbol

The speed symbol refers to the maximum speed capability of a tire. It is only valid for a tire that is properly inflated and loaded within the limits of the assigned load index.

Sidewall Information

YOKOHAMA: Manufacture’s name

ADVAN Sport: Brand Name

205/55R16 91W: Tire Size Designation

V105: Tread Pattern Name

Country of Origin

Identification Serial Number

MAX LOAD, MAX PRESS

Safety Warning

Asymmetrical tread pattern and specified tire rotation

Tires with a directional pattern need to be mounted according to the indications on the sidewalls to ensure maximum performance. Make sure you take note of the directional pattern when mounting the tire.

Unidirectional tread pattern

Tread pattern of V701

Asymmetrical tread pattern SIDE FACING OUTWARDS (INWARDS)

Tread pattern of V552

Sidewalls indicate whether they should face inwards or outwards.

It is vital to take note of the arrow when rotating tires to ensure that the tires are mounted in the correct direction.

Asymmetrical tread pattern and specified tire rotation

Tires with a directional pattern need to be mounted according to the indications on the sidewalls to ensure maximum performance. Make sure you take note of the directional pattern when mounting the tire.

Unidirectional tread pattern

Tread pattern of V701

Asymmetrical tread pattern SIDE FACING OUTWARDS (INWARDS)

Tread pattern of V552

Sidewalls indicate whether they should face inwards or outwards.

It is vital to take note of the arrow when rotating tires to ensure that the tires are mounted in the correct direction.

OE approval mark by automakers

Some tires may include a mark of approval from a specific automaker on the sidewall. There is no difference in basic performance if the tires are of the same size and pattern, irrespective of whether the mark is evident or not.

☆=BMW Specification

MO is a Mercedes-Benz approved mark.

N-1 and N-0 are Porsche approved mark.