They’re better tires, that’s why. Lower speed rated tires don’t perform as well as the higher speed rated tires, even at lower speeds.
And it’s a preference too, they don’t handle the same. If all you ever do is cruise to the Dairy Queen and the local show it doesn’t much matter. If you like more spirited driving, the higher rated tires perform better even if you don’t use them at the maximum sustained speeds they’re rated for. Just added insurance too, like running larger brakes than what you need to stop the car around town on a nice dry day. Because when it matters the conditions probably won’t be ideal.
