A penny can be used in which part of vehicle maintenance?

Using a penny to check tire tread depth is a common practice among drivers to ensure their tires are safe for the road. The method involves inserting the penny into the tread groove of the tire with Lincoln's head down. If you can see the top of Lincoln's head, it indicates that the tread depth is too shallow, and the tire may need to be replaced for safety reasons.

Adequate tread depth is crucial for maintaining traction, especially in wet or slippery conditions, as it helps water to be channeled away from the tire surface and prevents hydroplaning. Monitoring tire tread depth with a penny is a simple and effective way for vehicle owners to perform a safety check without needing specialized equipment.