What tool is commonly used to measure tire tread depth?

The best tool for measuring tire tread depth is a tread depth gauge. This specialized instrument is designed specifically for this purpose and provides accurate measurements of tire tread wear. It typically features a dial or a digital display that indicates the depth of the tread in millimeters or 32nds of an inch, making it easy to assess whether tires are within safe limits for performance and safety.

While other tools like a ruler or caliper might provide some level of measurement, they are not optimized for tire tread depth assessment. A ruler can be imprecise and difficult to read accurately due to the curved surface of the tire, while a caliper, although capable of measuring depth, is not designed specifically for this application and may not offer the ease of use or accuracy that a dedicated tread depth gauge provides. A pressure gauge is unrelated to tread depth measurement and is used solely for assessing tire inflation.