Tire design is typically focused on how the rubber interacts with the road, but what about the atmosphere?
Yokohama has been developing a new concept tire that can improve both a car’s efficiency and handling by redirecting the air around it. The design involves small fin-like protuberances built into the outside of the tire near its shoulder, where the sidewall meets the tread.
Mounted at alternating angles, when they reach the top of the tire’s rotation they help to reduce aerodynamic drag, which improves high speed fuel economy and, potentially, the top speed of the vehicle. At the bottom, aerodynamic lift is reduced. That keeps the vehicle better planted to the road, a particularly important characteristic for high performance sports cars.
The technology was made possible by recent advances in computational fluid dynamics. It builds on earlier research that found that radial fins positioned perpendicularly to the tread on the inside of the tire could also reduce the overall drag of a vehicle by changing the air pressure within the wheel wells.
Production applications have not yet been announced, but the concept tires are being introduced at the 2015 Tokyo Motor Show.