DISCOVER THE TYRE MARKINGS
In addition to the tyre size and the service description, on the tyre sidewall there are several different inscriptions: let's have a look at some of them.
When a tyre bears the European Noise Approved number this means it is compliant with Directive 2001/43/EC, respecting the new noise emission levels set for the European countries.
When a tyre bears the ECE symbol, this means it is ECE certified and approved to meet ECE standards for physical dimensions, branding requirements and high speed endurance regulations. The marking is made up of the letter E and a number representing the country releasing the approval sheet, followed by a unique number combination for each product.
DOT (Department Of Transportation) is a legal marking required in many countries in order to sell the tyres. DOT means the tyres meet or exceed the Department of Transportation’s safety standards.
1) Means tyre meets or exceeds Department of Transportation safety standards
2) Manufacturer and Plant Code Number (Assigned by DOT)
3) Tyre Size Code Number
4) Group of Optional Symbols for the Manufacturer ( To identify the brand or other significant characteristics of the tyre)
5) Date of manufacture
For all asymmetric products it is important to fit the tyre on the rim in the correct position. In fact asymmetric tread pattern designs are developed to offer the best performance considering the different behaviours of the external and internal areas of the tread design.
Winter tyres, also called snow, cold weather or thermal tyres, and identified by the branding M+S (Mud&Snow) on the side of the tyres together with the drawing of a mountain with a snowflake. Legally the M+S marking alone is sufficient to identify a winter tyre, but the tyre industry has adopted the snowflake marking to differentiate real winter tyres (M+S and snowflake) from all-season tyres (only M+S).
This example shows a typical tubeless radial tyre.
TWI is an important safety feature that easily allows how much tread is left on the tyre to be verified. Narrow bars of rubber are moulded at a height of 1.6 mm (2/32”) across the bottom of the tread grooves. When the tread wears down to these bars, the tyre should be replaced.
UTQG is a standard defined by the DOT of the USA for grading the
performances of tyres in the areas of TREADWEAR, TRACTION and
TEMPERATURE RESISTANCE. It applies only to car tyres with a rim diameter
of 13" and larger, but not to winter tyres.
TREADWEAR: The treadwear grade is a comparative rating based on the wear rate of the tyre when tested under controlled conditions on a specified government test course. For example, a tyre graded 150 would wear one and one-half times as well on the government course as a tyre graded 100. The relative performance of tyres depends upon the actual conditions of their use, however, and may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate.
TRACTION: The traction grades, from highest to lowest, are AA, A, B, and C. These grades represent the tyre's ability to stop on wet roads as measured under controlled conditions on specified government test surfaces of asphalt and concrete. A tyre marked C may have poor traction performance. Caution: the traction grade assigned to the tyre is based on straight-ahead braking traction tests, and does not include acceleration, cornering, aquaplaning, or peak traction characteristics.
TEMPERATURE: The temperature grades are A (the highest), B, and C, representing the tyre's resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel. Sustained high temperature can cause the material of the tyre to degenerate and reduce tyre life, and excessive temperature can lead to sudden tyre failure. Grade C corresponds to a level of performance which all passenger car tyres must meet under the Federal Motor Safety Standard No. 109. Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law. Caution: the temperature grade for this tyre is established for a tyre that is properly inflated and not overloaded. Excessive speed, under inflated tyres, or excessive loads, either separately or in combination can cause heat build-up and possible tyre failure.