Drive belts, typically serpentine or V-type, transmit power from the crankshaft to various engine-driven accessories including the alternator, power steering pump, air conditioning compressor, and water pump. Constructed of reinforced rubber compounds with varying tensile strengths, these belts are designed to withstand high temperatures and continuous flexing. Modern serpentine belts utilize multiple ribs for increased contact area and efficiency, replacing multiple V-belts in many applications. Tension is maintained via automatic or manual tensioners to ensure proper operation and prevent slippage. Belt materials include EPDM, HNBR, and PCU blends optimized for specific vehicle requirements and service intervals.