Arqray focuses on the performance, quality, and sound of all their exhaust systems. A feature of every Arqray exhaust system is the tube diameter that is very carefully selected for each and every car, depending on the engine's displacement and characteristics. This allows an increase in performance and sound while remaining true to the OEM smoothness that BMW excels at. Arqray torque and power curves are generally flatter and more linear than other exhaust systems. Each exhaust is also tuned to free up the engine's sound while still letting the engine's characteristics shine through.