Interpretation ID: nht80-3.49

DATE: 09/18/80

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Uniroyal Tire Company

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of August 14, 1980, requesting interpretation of the Uniform Tire Quality Grading (UTQG) Standards (49 CFR @ 575.104) with regard to the assignment of treadwear grades. You report that Uniroyal has encountered variations in treadwear test data derived from UTQG tests conducted by different testing organizations. You ask whether a tire manufacturer is obligated under the UTQG treadwear grading procedure to base its grades on those test results which produce the lowest treadwear grade, or may use any available test data as the basis for grade assignment.

Uniform Tire Quality Grading, as with other National Highway Traffic Safety Administration (NHTSA) regulations, involves a self-certification process in which manufacturers bear the primary responsibility for assuring that their products conform to required levels of performance, in this case the levels represented by their assigned grades. NHTSA's Office of Vehicle Safety Compliance (OVSC) conducts testing to verify that various tires actually provide levels of performance consistent with their grades. When OVSC testing produces results at variance with assigned grades, the manufacturer involved is given an opportunity to provide justification for its grade assignments.

In determing that a product achieves a particular level of performance under the UTQG procedures, a manufacturer may exercise a considerable degree of discretion as to the amount of testing necessary to assure that its conclusions regarding compliance will withstand NHTSA scrutiny. In evaluating the performance of a product, NHTSA does not require that a manufacturer base its judgment on any particular piece of test data or on all available data. In fact, a manufacturer may disregard data from a particular source entirely, if the manufacturer can establish that other data provides a reasonable basis for grading.

However, a manufacturer cannot establish compliance by arbitrarily picking and choosing among available data to select results of that test which happened to produce the most favorable result. Data used to establish compliance must be reliable and consistently reproducible, and cannot have been derived through manipulative devices, e.g., abusive driving, or unexacting test procedures. It is the responsibility of the manufacturer to base its conclusions on data demonstrably developed in full conformance with the requirements of the regulation.

NHTSA will provide confidential treatment for your letter of August 14, 1980, and the accompanying data.