Interpretation ID: nht94-1.45

TYPE: INTERPRETATION-NHTSA

DATE: February 7, 1994

FROM: Martin M. Sackoff, Ph.D. -- Executive Director Of Laboratories, International Testing Laboratories

TO: Office of Chief Counsil -- NHTSA

TITLE: None

ATTACHMT: Attached To Letter Dated 5/12/94 From John Womack To Martin Sackoff (A42; Std. 109)

TEXT: Gentlemen:

The subject of this request is in reference with Motor Vehicle Safety Standard No. 109 - New Pneumatic Tires - Passenger Cars.

The specific question is with reference to S4.2.2.4 Tire Strength, which states "S4.2.2.4 Tire Strength. Each tire shall meet the requirements for minimum breaking energy specified in Table 1 when tested in accordance with S5.3".

I shall very much appreciate receiving a reply concerning the definition or interpretation of the term "breaking" of the tire. Does this mean a blowout of the tire, or simply the breaking of the tire caused by forcing the steel plunger into the tread?

Thank you.

Sincerely,