CP Piston & Ring Set for Subaru EJ257 WRX STI - Bore (99.5mm) - Size (STD) - CR (9.0) - Set of 4

CP Pistons is known for making strong internal engine components, and this piston and ring set is a solid example for your 2004-2012 Subaru Impreza WRX STI. If you're rebuilding the engine in your EJ257, these pistons are built to handle the demands of a performance application. They come in a standard bore size of 99.5mm, which is ideal if you're not boring out the cylinders further, and feature a 9.0 compression ratio. This set includes four pistons and their matching rings, ready for installation.

These are forged pistons, meaning they start as a solid block of aluminum that's heated and hammered into shape. This process creates a much stronger and more durable piston than cast aluminum, which is important for engines that see hard use or are modified for more power. The standard bore size and 9.0 compression ratio make them a good choice for many EJ257 builds where you want reliable performance without going too extreme on compression. You'll want to ensure your engine is properly balanced and that you follow the manufacturer's installation instructions for best results.