When checking valve clearance, what is the best gauge to use?

Using a standard feeler gauge is the best choice for checking valve clearance because it is specifically designed for this purpose. Feeler gauges consist of a set of thin, flat pieces of metal with precise measurements, allowing a mechanic to easily determine the gap between the valve and the rocker arm or adjusting screw. This process is crucial in ensuring proper valve operation, which affects engine performance, emissions, and overall functionality.

While other tools like a dial gauge or digital gauge can measure distances, they are more suited for different applications, such as measuring linear displacement or checking tolerances, and are not typically used for valve clearance checks. An inside micrometer, on the other hand, is intended for measuring the internal dimensions of cylindrical objects, which does not apply to valve clearance. Therefore, the feeler gauge remains the most practical and efficient tool for this specific task.