Your engine has a number of mechanical accessories attached to it, such as an alternator, water pump, power steering pump and an air conditioner compressor. A drive belt is the part that drives all these accessories. The belt itself is driven by a pulley attached to the engine crankshaft. Most cars have one or two drive belts. When a car has only one drive belt, it might be called a serpentine belt.
A drive belt is made of a durable rubber-based material. In most cars, a drive belt is replaced between 40,000 and 70,000 miles, however, we have seen cases where a drive belt lasted over 100k miles. What makes the belt wear sooner? Water, road dirt, excessive heat and oil leaks can cause the belt to deteriorate prematurely. For example, if the protective shield underneath the engine (engine undercover) is broken, the belt will wear out sooner. Oil leaks can also damage the drive belt. Eventually, a worn drive belt will break.
If the drive belt breaks, your car won’t be driveable. This is because the engine will overheat if the water pump is not running. Also, if your car has a hydraulic power steering, you will lose the steering assist, as the power steering pump will be disabled. In addition, the alternator will stop supplying electric power that is needed to recharge the battery and run the vehicle electric systems.