Interpretation ID: 1985-02.2

TYPE: INTERPRETATION-NHTSA

DATE: MARCH 20, 1985

FROM: LARRY GIFFORD -- SERVICE REP., YOKOHAMA TIRE CORPORATION

TO: WES SPRUNK -- SAF-TEE SIPING & GROOVING INC.

TITLE: NONE

ATTACHMT: DECEMBER 30, 1988 LETTER FROM JONES TO SPRUNK, OCTOBER 8, 1987 LETTER FROM SPRUNK TO JONES, BROCHURES ON TIRE SIPING, 1978 NSC WINTER TEST REPORT, AUGUST 19, 1986 LETTER FROM KEIL TO SPRUNK, ARTICLE FROM AUGUST 19, 1986 ISSUE OF "SCHOOL BUSINESS AFFAIRS," ARTICLE ENTITLED "SLASHING TIRES FOR SAFETY AND SAVINGS" FROM DECEMBER 1984 "NATIONAL SCHOOL BUS REPORT," OCTOBER 15, 1982 LETTER FROM PALMER TO MARCY MANUFACTURING, AND APRIL 1983 AND APRIL 1984 ARTICLES FROM "GW SAFETY TALK"

TEXT: Reference is made to our conversation concerning truck tire siping at the N.W.T.D.A. meeting here in Portland 2/7/85.

Several of our dealers, mainly in Montana and Colorado, have been making this service a practice for many years. In doing so, it achieves three main benefits; improved traction, less free roll wear on radials (steer & trailer positions) and extends mileage.

I also mentioned going a step further and have had three sets of our logging tires siped at 11/32 depth. The tire is our 710 and originates with 25/32. The results were about 40% less usage of chains; less abrasive damage to tread area and 7-10% more mileage. The tires are not to recap stage, but I do not expect any carcass failures from the siping.

I surely recommend this service now in all types of tire usage.