DOT Number
When you see “DOT” molded into a tire’s sidewall, it indicates that the tire meets the U.S. Department of Transportations tire safety standards and that it is allowed to be used on the highway in the United States. Following “DOT” will be a series of letters and numbers that convey a great deal of important information, starting with the manufacturer and plant code. They are found in the first two letters, while the size is indicated by the third and fourth characters. The fifth, sixth, seventh and eighth (optional) characters indicate the brand and other information about the tire. The next two numbers indicate the week the tire was made. The final numbers indicate the year.
ECE
The European equivalent of DOT approval is ECE approval. It comes from the Economic Commission of Europe, which develops motor vehicle requirements much like our DOT does. Tires that earn ECE approval must meet standards for dimensions, branding and high-speed endurance, and pass stringent tests in an ECE-endorsed laboratory. Once approved, tires are certified for use in Europe according to the load index and speed symbol shown in the service description.
Approval is indicated by a letter and number indicating the country where approval was obtained, set within a circle. This symbol is molded into the sidewall next to a series of numbers that identify the Regulation Amendment Series under which the tire was approved.
M+S
The Rubber Manufacturers Association (RMA) uses three designations to indicate that a tire meets its definition of a mud and snow tire: M+S, M/S, and M&S.
Officially Qualified for “Severe Snow Conditions”
An industry standard and testing procedure have been established for passenger and light truck tires for use in severe snow conditions based on a voluntary definition now recognized by members of the Rubber Manufacturers Association and Rubber Association of Canada. Tires meeting the performance-based criteria of this definition feature tread patterns, construction elements and materials that provide superior snow performance over tires meeting the existing RMA snow tire definition.
The Toyo Observe has met that standard with room to spare and will sport the new Mountain Snowflake sidewall icon for such tires. Toyo Tires recommends that snow tires should be installed in matched sets of four.
