Toyo Tires made national news lately with a story that they’re adding walnut shells to their Observe tire line.
There’s only one problem with that statement: Toyo’s Observe line of winter tires has actually had what they call Microbit Technology for 25 years. So we thought it was time to revisit what this technology is and set the record straight.
How Microbit Technology works
Mineralogists classify the hardness of things using the Mohs Scale of hardness. This ranks the hardness of minerals on a scale of one to ten, with talc being a one (the softest) and diamonds being a ten (the hardest). Walnut shells are a four on the scale, meaning they’re in the middle, along with other minerals such as Fluorite, Azurite, Malachite and Pyrrhotite.
The walnut shells are ground up and infused into the rubber of the tread. Some are embedded in the tread while other pieces are left exposed. The way they are ground up leaves sharp edges on the pieces of shell. These sharp edges dig into the ice, giving the driver better traction than tires without this technology. As the tire wears, more sharp edges are exposed, actually increasing the amount of traction given.
Field Services Manager for Canada John Carpenter told us: “Toyo Tires is on the third generation of walnut shells, using larger shell fragments, resulting in better grip on slippery surfaces.”
Although the walnut shell is already quite hard, it is treated during the purification process to make it even harder. This process also helps them adhere to the rubber compound even better.
Dispersion rate is the paramount concern during manufacture
Mixing walnut shells into the rubber compound isn’t a difficult proposition. However, Carpenter says that getting the dispersion rate right is the hard part and that Toyo spent many years trying to do just that. He says that slippery surface traction is degraded if the dispersion of the shells isn’t just so.
Julie Sediq, Toyo’s senior manager of marketing communications, said all three Observe lines — Observe GSi-5, Observe Garit KX, and Observe G3-Ice — incorporate the walnut shell technology.
When Toyo Tires was on the hunt for how to make winter tires produce even better traction on snow and ice, numerous natural and manmade materials were tested. Walnut shells were found to perform better than anything else tested. The fact that they are a renewable resource is an added bonus for the company and environment.
Observe fitment information
Toyo’s Observe GSI-5 Studless Winter Tire fits almost everything on the road today. Tire sizes range from 188/80R13 at the small end up to 315/35R20 at the large end of the fitment chart. This means they fit small cars like older Honda Civic CVCC models and newer SUVs like the Cadillac Escalade, as well as light trucks and minivans.
The Observe Garit KX uses a slightly different tread pattern to give passenger cars excellent traction in wet weather and icy conditions. Sizes range from a 195/55R15 up to a 245/40R19, putting them smack in the large passenger car, light truck, and SUV category. They can be found on Chevy Impalas; Ford F-150s, Escapes, and Explorers, and Dodge Durangos.
The Observe G3-Ice is a studdable passenger and light truck tire that is designed for maximum snow and ice traction, while sacrificing a little wet and dry performance. Sizes range from the low end of 175/70R13 (Honda CVCC, etc.) up to a 285/45R22. They’ll fit the Impala, Silverado, Sierra, Tundra, most minivans, and most SUVs like the Explorer, Escape, Expedition, and Durango.
Tires with Microbit Technology are multi-surface capable
While Toyo Observe tires are designed for use on snow and ice, they can be used anywhere. Carpenter says there is no degradation to ride comfort or addition to the amount of road noise generated by the tires when used on asphalt surfaces. He says that Observe tires are much quieter and more comfortable than tires with studs. Additionally there are no states or locales that prohibit their use on public roads, unlike studs and chains.