PERRIN 02-05 Subaru WRX / 04-06 STI / 93-11 Impreza Lightweight Alternator Pulley - Black

This is the Perrin lightweight alternator pulley for your 2002-2005 Subaru WRX, 2004-2006 STI, or 1993-2011 Impreza. It's designed to replace the stock alternator pulley, which is heavier and has more rotational mass. By reducing this mass, the engine doesn't have to work as hard to spin the alternator, potentially leading to a slightly improved throttle response.

Perrin makes this pulley from well-built aluminum and then anodizes it black for a clean look under the hood. It's a direct replacement part, meaning it bolts right up where the original pulley was. While it's a small change, for those looking to shave off every bit of weight and improve engine responsiveness, this pulley is a solid option.