Which tool is commonly used to measure tire tread depth?

The correct answer is a tread depth gauge, which is specifically designed for measuring the depth of the tire tread. Tire tread depth is crucial for safety and performance, as insufficient tread can lead to reduced traction, especially on wet or slippery surfaces. A tread depth gauge allows for precise measurement, enabling the driver or inspector to determine if the tires meet minimum legal requirements and are safe for operation.

While a ruler could theoretically be used to measure tread depth, it is not as accurate or convenient as a tread depth gauge, which often features a simple design that provides clear readings. On the other hand, a pressure gauge is used to check tire inflation pressure, and a torque wrench is intended for tightening bolts to a specified torque. These tools, while essential in their respective areas, are not appropriate for measuring tread depth.