Interpretation ID: nht73-3.36
DATE: 03/02/73
FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA
TO: Semperit of America, Inc.
TITLE: FMVSS INTERPRETATION
TEXT: This is in reply to your letter of January 25, 1973, inquiring whether size designations "225/70SR14 replaces G70SR14", and "215/70SR15 replaces F70SR15" etc., may be used under Federal Motor Vehicle Safety Standard No. 109.
Paragraph S4.3(a) of Standard No. 109 provides for the labeling of "one size designation, except that equivalent inch and metric size designations may be used." The NHTSA has taken the position that this requirement does not prohibit the labeling of replacement sizes when the replaced size is in fact being superseded by the replacement size.
Because your proposed label contains both a metric and an inch size designation, however, it is not clear whether these size designations are intended as "equivalent" or "replacement" sizes. If you intend the former size to supersede the latter, your use of "replaces" between the two size designations is consistent with Standard No. 109. If your intention is to label equivalent size designations, however, the use of "replaces" is inappropriate One way in which equivalency may be appropriately shown is to place the inch size designation in a parenthesis () immediately following the metric size designation.
One last point is that the size designations listed in the Appendix of Standard No. 109 for 70 Series radial ply tires differ from those specified in your letter. Table I-G, which lists this tire type, specifies size designations in which the second letter is an "R". Thus, the size designations which you submit should have read GR70SR14 and FR70SR15. Other size designations of this tire type should be identified accordingly.