The Toyo Observe line of winter tires offer impressive traction during the slippery winter months without resorting to tire studs that are banned on many roads. Rather than studding the Toyo Observe line, the tire manufacturer looked to nature for a grip solution, and it found it from an unlikely source: nuts.
The treads on Toyo Observe tires are coated with purified walnut shells. Anyone who's cracked a walnut knows that the shells are incredibly tough, and when broken down to a microscopic level, the walnut shell shards in Toyo Observe tires crack though the surface of ice to provide added friction.
While hard enough to crack through sheets of ice, the walnut shells are still softer than pavement, making Toyo Observe tires completely safe for driving city roads.