Our nickies kits for Boxster & Cayman models includes custom forged side relief je pistons, including coated skirts, split oil returns, quench pads, and accumulator grooves, just like the factory pistons. This allows for faster burn and better thermal efficiency, leading to better gas mileage, lower potential for detonation, and more power by retaining the factory inverted dome piston shape, mirroring the pent-roof four-valve combustion chamber! Forged pistons are superior to the factory cast pistons found in non- s model engines and are as strong as the forged pistons found on s engines, but use a lightweight forged side relief design for improved strength while being lighter than the factory pistons.