Tire Wear: Notes

Measure the tread depth of the tires.
Tread depth [limit]: 1.6 mm (0.0630 in.)
If the remaining tread depth (A) is less than the limit, replace the tire.
NOTE: When the tread depth of the tires is less than 1.6 mm (0.063 in), the wear indicators (B) will appear.

Courtesy of KIA MOTORS AMERICA, INC.