1994 Buick Roadmaster Owner's Manual - Page 262

J The grade C corresponds to a level performance of which all passenger car tires must meet under the No. 109. Grades Federal Motor Vehicle Safety Standard B and A represent higher levels performance on the of laboratory test wheel than the minimum required by law. Warning: The temperature gradefor this tire is established for a tire that is properly inflated and not overloaded. Excessive speed, underinflation, or excessive loading, either separately or combination, in can cause heat buildup and possible tire failure. of These grades are molded on the sidewallspassenger car tires. While the tires available ,as standard or optional equipment on General Motors vehicles vary with may respect to these grades, such tires meet General all Motors performance standards have been approved and for use on General Motors vehicles. All passenger type (P Metric) tires must conform to Federal safety requirements in addition to these grades.