Consumer Information Regulations: Uniform Tire Quality Grading Standards

This final rule amends the Uniform Tire Quality Grading Standards to: Revise treadwear testing procedures to maintain the base course wear rate of course monitoring tires at its current value of 1.34. This revision is expected to eliminate treadwear grade inflation, reduce testing expenses, and reduce the environmental consequences of operating test convoys for the purpose of calculating the base course wear rate for each new batch of course monitoring tires; and add a top end traction grading category of ``AA'' to the current traction grading categories of A, B, and C. The new AA category will make possible the differentiation of tires with the very highest traction characteristics from those with lower traction characteristics.