Porsche 718 Cayman GT4 RS Maintenance & Service Schedule The Porsche 718 Cayman GT4 RS is the most extreme Cayman ever built, featuring a 9,000 RPM 4.0L flat-six from the 911 GT3, aggressive aerodynamics, and a lightweight motorsport-inspired chassis. Designed for track performance and high-revving thrills, the GT4 RS demands...