Final answer:
The tread depth of a tire should be between 4/32 and 6/32 of an inch, but newer recommendations suggest deeper tread depths. This ensures proper traction and handling of the vehicle.
Step-by-step explanation:
The tread depth of a tire refers to the measurement of how deep the grooves in the tire are. It is important to have adequate tread depth for proper traction and handling of the vehicle.
The recommended tread depth for tires is typically between 4/32 of an inch and 6/32 of an inch. However, some newer recommendations suggest a tread depth of up to 8 diameters side-to-side and 15 diameters deep. This means that if the diameter of the tire is 20 inches, the tread depth could be up to 8 inches side-to-side and 15 inches deep.