Similar to Alpes, Here is what CHP says:
R1: Chains are required - snow tread tires allowed.
R2: Chains are required on all vehicles except four wheel drive vehicles with snow tires on all four wheels.
R3: Chains are required - all vehicles - no exceptions.
R1 and R2 are the most common conditions. The highway is usually closed before an R3 condition is imposed.
The Toyo tire we have is (M+S) so no chains are required in R1/R2 but we still need to show CHP that we are carrying one just in case conditions worse to R3. I got an almost undersized chain and test fitted without the clearance issue.
Please keep in mind this is the minimum to pass CHP inspection. Doesn’t mean is safe...
I don’t have real world experience yet. It has been snowing in the mountains for two weekend straight and my daughters have been under weather one after another.
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