With a winter tire you can quadruplicate your safety. With a deeper tread and 5 times more cuts than a summer tire, a winter tire can easily remove water and provides maximum grip in winter conditions (ice, snow, wet, dry). Furthermore, winter tire's rubber compound is more flexible, richer in silica and more effective below 7°C. Therefore, winter tires provide better performance than the summer ones under 7°C even on dry or wet roads. In particular, official measurements have estimated that under 7°C you can earn 6 feet in braking distance on wet roads with winter tires.
Moreover, it is very important to equip your vehicle with 4 winter tires, rather than 2, otherwise there is a strong risk of drifting and generally you cannot ensure the right behavior of the vehicle.
Conclusion: For better grip in winter and particularly when the temperature is under 7°C, the only safe solution is to put 4 winter tires on the vehicle.
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