Well, they actually have been for a while … that is to say, they’ve been using nuts in their winter tire technology. Toyo uses crushed walnut shells in their winter tread compound along with other things like bamboo carbon and silica, to produce a technologically advanced rubber compound in each of their Observe .
When I first heard this I was curious and wondered why walnut shells or bamboo carbon would be used when there are so many other man-made “chemically produced” compounds that they could use similar to competitive products. Toyo decided that they wanted to do their part and be as environmentally responsible as possible. Toyo started an initiative called “Tecology” combining “environment” and “technology” to look towards making green decisions, especially when it enhances the product line. Things like walnut shells and bamboo carbon are a renewable resource so Toyo doesn’t have to artificially produce them from chemicals or fossil fuels which harm the environment.
Also, the uses of these specific natural products are unbeatable! Black walnut shells are one of the hardest substances in the world and their texture is very efficient. The bamboo carbon is very porous making it very absorbent.
You may be asking, “Why do we need these substances in winter tires in the first place”? That’s a good question especially when we usually think of a winter tire’s tread doing all the work in snow. The answer is that a modern winter tire is unbeatable in snowy conditions but they also work great on ice, slush and even cold dry roads. This is why Toyo refers to them as “Cold Weather” tires, not just winter tires.
It’s common for tires to come with studs for severe winter service. These studs are very efficient on icy or compact snow covered roads. Although studded technology is getting better at this time they are still noisy and may even have reduced traction when stopping or turning on dry clear roads. Not to mention that many provinces and states have made them illegal due to the damage they cause to paved roads.
Toyo uses a studless technology which incorporates crushed walnut shells which act like tiny spikes that dig into icy, compact snow while not diminishing the effectiveness of the tire on dry roads. To help visualize how they work on ice, imagine going to your local ice rink with a sheet of sandpaper in your hand. Turn it rough side down onto the ice and try scrubbing the ice. It would be very hard to move and would actually scratch the ice. In principle, this is how studless technology works. The walnut shells work perfectly for this task as they break up into sharp edged particles.
Bamboo carbon is very porous which allows it to absorb water. If you used a microscope on an icy road
you would see that in many cases there is a fine film of water. This water could reduce the tires ability to make contact to the road. The black carbon acts like a sponge to reduce the effect of the water. Think of it like a regular hockey puck out on ice. If you slide it along it will glide for some time. Now take one of those “sponge rubber” street hockey pucks and try doing the same thing. The soft rubber puck will not slide because the porous surface absorbs the water and lets the rubber stick to the ice.
If we look deeper at a regular hockey puck, if you freeze it before you slide it on the ice, it will slide even easier. Using silica in a tire compound helps ensure the tread compound will not freeze and stiffen, keeping flexible or supple so the tread blocks make positive contact with the surface further ensuring the winter technology can do its job.
These are just a couple of the advancements in the design of a winter tire. Things like advanced spider sipes, saw toothed edge blocks and much more make winter tires even safer than before. Now the real trick is finding the right mix of compounds, along with the right tread design, to make this all come together. This is accomplished by years and years of testing and re-testing.