Most drivers don't often think about the temperature of their tires, but rubber that has too much ice or snow buildup can significantly reduce traction—even winter tires. Mercedes-Benz appears to be thinking about tire temperatures, though.
Mercedes' parent company, Daimler, recently filed for a patent in the United Kingdom for a device that would spray a liquid on a vehicle's tires. The patent image shows three spray nozzles shooting the tire from different angles. The filing suggests that Daimler is looking to use the system to melt snow and ice, at least initially. A system to cool down tires that are overheating would need to rely on a thermal imaging camera, something Daimler mentions in the filing but admits is full of limitations.
The patent says that the control unit would actually collect water that rolls off of the vehicle's rear window, a solution that reduces or eliminates any need to constantly refill a reservoir. The filing indicates that the collected water would be "rainwater, water from a car wash, or melting ice or snow." A heat exchanger would then keep the water from freezing in the winter. No mention of an antifreeze agent is made for this particular filing, though previous efforts to solve ice buildup on tires in winter have included ethylene glycol.
If and when this type of system would be implemented is yet to be seen, but it's nice to know that Mercedes is at least thinking about it.