NHTSA changes snow, LT tire testing parameters
Snow tires will be subject to relaxed testing standards, thanks to a recent amendment to Federal Motor Vehicle Safety Standard No. 139 made by the National Highway Traffic Safety Administration (NHTSA). The agency also has excluded radial light truck tires with tread depths of 18/32-inch or more from the standard.
Changes "reduce the endurance and low-pressure test speeds from 120 kilometers per hour to 110 kilometers per hour for snow tires," say NHTSA officials.
Radial light truck tires with the aforementioned tread depths will now be subject to FMVSS No. 119. (FMVSS No. 139, which NHTSA established in June 2003, applies to new tires used on vehicles with a gross vehicle weight rating of 10,000 pounds or less, excluding motorcycles and low speed vehicles.)
The changes will become effective June 1, 2007.