While all-season tires handle many conditions adequately, they often fall short in heavy snow or ice. All-weather tires offer improved grip without being full winter tires and commonly display the 3PMSF symbol on the sidewall. This rating differs from the basic M+S marking, which relies only on tread design chosen by the maker. Instead, the 3PMSF requires passing a formal performance test known as ASTM F1805 from the American Society for Testing and Materials.

To earn the symbol, a tire must achieve at least 12 percent better acceleration traction than the standard reference test tire. The reference model has shifted from a P195/75 R14 size with a 10 percent threshold to the current P225/60 R16 size under updated ASTM F2493 rules.

Testing follows strict protocols outlined in related research on winter traction. The snow surface must be medium-packed, with air temperature no higher than 38 degrees Fahrenheit and snow temperature between 5 and 25 degrees Fahrenheit. A CTI penetrometer confirms the snow shear strength before runs begin. The candidate tire mounts on a specialized truck, spins on the prepared surface, and its traction coefficient is measured against the reference tire to determine overall performance.

The procedure focuses solely on acceleration and does not assess braking or cornering, which explains why some all-season tires have outperformed certain 3PMSF-rated all-weather models in real-world evaluations by Tire Rack.

Exploring the New Ice Grip Designation

Dedicated winter tires surpass all-weather options on ice and may carry an additional Ice Grip symbol depicting a mountain with an ice crystal. This marking demands compliance with the ISO 19447:2021 braking standard from the International Organization for Standardization.

Tires such as the Nokian Hakkapeliitta R5, frequently praised by Consumer Reports, display this symbol after completing multiple brake tests on polished ice. The tire must deliver at least 18 percent better stopping grip than the reference tire per ASTM F2493. Test conditions require a flat ice surface with temperatures between 5 and 23 degrees Fahrenheit and air temperature (measured three feet above the surface) between 5 and 39 degrees Fahrenheit, with no precipitation.

A vehicle equipped with ABS and capable of fitting various wheel sizes is used. Tires are inflated to recommended pressures and broken in over 62 miles of dry pavement. The evaluation consists of repeated braking runs across three cycles, measuring grip from speeds of 12 to 15 mph until a full stop. As a recent addition to tire ratings, the Ice Grip mark helps buyers identify models that excel at stopping on ice beyond the snow-traction assurance provided by the 3PMSF symbol alone.