Interpretation ID: aiam1655
8 North Queen Street
Griest Building
Lancaster
Pennsylvania 17603;
Dear Mr. Thomas: This is in reply to your letter of September 27, 1974, requesting ou position regarding the micro-siping of tires. You also request copies of the government brief in *United States* v. *General Tire*.; The NHTSA does not consider the micro-siping process to be prohibite *per se* when applied to new motor vehicle tires subject to either Motor Vehicle Safety Standard No. 109, 49 CFR S571.109 (applicable to passenger car tires), or Motor Vehicle Safety Standard No. 119, 49 CFR S571.119 (applicable to tires for vehicles other than passenger cars). In the *General Tire* case, the particular tires involved havebeen(sic) micro-siped and were found to have failed certain laboratory wheel tests specified in Standard No. 109. The only issue in the case was General's responsibility for the failure and not whether the tires met the standard. General chose to stipulate that they did not.; The agency has no data on whether micro-siping adversely affects tire's ability to conform to the standards. It is possible that the quality of micro-siping may cause compliance problems. In any event, the agency does not consider micro-siped tires to fail to conform to either standard, unless there is an actual failure to meet the performance tests of the standards.; I have enclosed a copy of the government's brief in the Court o Appeals in the *General Tire* matter. There are other briefs in this litigation, but the agency's position is set forth in this brief and it should be satisfactory for your purposes.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Acting Chief Counsel