Law & Order

NHTSA Issues Final Rule to Update Standard Reference Test Tire

The National Highway Traffic Safety Administration (NHTSA) has issued a final rule to update the standard reference test tire (SRTT) used as a baseline tire to rate treadwear, braking traction, snow traction and evaluate pavement surface friction. The rule was necessary because the only manufacturer of the previously referenced SRTT ceased production of the tire. Referencing a new SRTT ensures the availability of a test tire for testing purposes.

Under the final rule, ASTM E1136, ‘‘Standard Specification for P195/75R14 Radial Standard Reference Test Tire’’ (14-in. SRTT) will be replaced with ASTM F2493, Standard Specification for P225/60R16 (16-in. SRTT). The 16-in. SRTT is considered more representative of current tires because of its larger size, new material and design features that are more typical of modern passenger car tires.

To view the final rule click here.

For more information, contact Caroline Fletcher at