This multi-ribbed belt drives the alternator from the engine crankshaft, maintaining tension across the pulley system to ensure consistent charging output. It is routed around the alternator pulley and any idler or tensioner pulleys in the drive loop. A worn or glazed belt slips under load, causing the alternator to undercharge and the battery to discharge over time. The 8PK profile matches the original pulley groove geometry, which keeps the belt seated correctly and prevents edge wear. On installation, verify that the tensioner is within its working range and that the belt tracks straight across all pulleys.