Interpretation ID: nht72-6.47

DATE: 10/05/72

FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA

TO: Gislaved

TITLE: FMVSR INTERPRETATION

TEXT: Thank you for your letter of September 21, 1972, in which you inquire about the use of the third grouping of characters in the tire identification number required by Regulation Part 574.

You are correct in your understanding that there has been no recent change in the regulation regarding the optional use of the third grouping for tire type (Illegible Word) purposes. The third grouping may be used by the manufacturer if he so desires to identify significant characteristics of the tire and he may use up to four symbols in the group. However, if the tire is manufactured for a brand name owner, the third grouping must be used to identify the brand name owner. The tire type code is not compulsory except to identify a brand name owner.

Apparently the organization that uses the enclosure accompanying your letter is making (Illegible Words) within its own operations of using a 10 character identification number even though the regulation does not make it mandatory. The National Highway Traffic Safety Administration has no objection to this practice.

We appreciate your concern for compliance with the regulation. Please let us know if we can be of further assistance.