Search Interpretations

Interpretation ID: nht95-2.82

TYPE: INTERPRETATION-NHTSA

DATE: May 17, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Stephen M. Padula -- Industry Standards and Government Regulations, Uniroyal Goodrich Tire Company

TITLE: NONE

ATTACHMT: ATTACHED TO 3/21/95 LETTER FROM STEPHEN M. PADULA TO WALTER K. MYERS

TEXT: Dear Mr. Padula:

This responds to your letter of March 21, 1995, in which you asked whether it is permissible to have a treadwear grade of 00 or 000 on tires under the Uniform Tire Quality Grading Standards (UTQGS), 49 CFR 575.104. The answer to your question is yes.

As you know, the UTQGS currently provide that all new passenger car tires sold in the United States must be graded by their manufacturers or brand name owners for treadwear, traction, and temperature resistance. The grades must be assessed in accordance with paragraphs (d)(1)(i)(A) and (B) of the UTQGS and must be molded into or onto the tire sidewall.

Paragraph (d)(2)(i) requires the treadwear grade to be expressed as 2 or 3 digits, representing the percentage (P) of the NHTSA nominal treadwear value, computed as follows:

Projected

P = mileage 30,000 X 100

The percentage derived from the above formula is then rounded off to the nearest lower 20-point increment to arrive at the treadwear grade.

In your letter you proposed a hypothetical example of a tire with a projected mileage of 5,000 miles, which would compute as follows:

P = 5,000 30,000 X 100 = 16.67

Rounded off to the nearest lower 20-point increment, the treadwear rating for that tire would be 00 or 000.

Your example would be correct, if tires still exist that have a projected tread life of 5,000 miles. Although NHTSA has not found any tires so rated, under the current provisions of the UTQGS, it is possible, as demonstrated by your example, to have a U TQGS treadwear rating of 00 or 000.

I hope this information is helpful to you. Should you have any questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992.