The Department of Transportation (DOT) mandates Quality Grades for all passenger car tires. All tires must conform to stringent federal safety requirements in addition to these comparative performance grades.

These quality grades are embossed on the tire sidewall, located in the area between the tread shoulder and the maximum section width. For example, a typical grading might appear as follows:

Treadwear 200 Traction AA Temperature A

Treadwear

The treadwear grade is a comparative rating derived from the wear rate of a tire when subjected to rigorous, controlled testing on a specialized government-specified test course. For illustrative purposes, a tire with a grade of 150 would be expected to last one and one-half (1 1/2) times longer on the government course than a tire with a grade of 100.

It is important to understand that the actual tread life of the tires on your Nissan Leaf depends heavily on real-world usage. Performance may depart significantly from the laboratory norm due to variations in individual driving habits, regular maintenance practices, road surface characteristics, and local climate conditions.

Traction AA, A, B and C

Traction grades are ranked from highest to lowest as AA, A, B, and C. These grades represent the tire's ability to come to a controlled stop on wet pavement, as measured under standardized conditions on government-specified asphalt and concrete surfaces. A tire assigned a grade of C may demonstrate poor traction performance in adverse weather.

WARNING

The traction grade assigned to a tire is strictly based on straight-ahead braking traction tests and does not encompass capabilities such as acceleration, cornering, hydroplaning resistance, or peak traction characteristics under all driving maneuvers.

Temperature A, B and C

Temperature grades range from A (the highest) to C, indicating a tire's resistance to heat generation and its capacity to dissipate heat when tested under controlled conditions on an indoor laboratory test wheel. Sustained high operating temperatures can cause the tire materials to degenerate, leading to a shortened lifespan, while excessive heat build-up can result in sudden, catastrophic tire failure.

A grade of C corresponds to the minimum performance level that all passenger car tires must meet according to Federal Motor Vehicle Safety Standard No. 109. Grades B and A represent performance tiers that exceed the minimum legal requirements on the laboratory test wheel.

WARNING

The temperature grade established for a tire assumes that it is properly inflated and not subjected to overloading. Factors such as driving at excessive speeds, operating with under-inflated tires, or carrying excessive loads—whether individually or in combination—can trigger rapid heat build-up and increase the risk of sudden tire failure.