The key to the efficient use of a single prime mover is the choice of a gas turbine that provides efficiency over a large load range; the WR-21 gas turbine incorporates compressor intercooling and exhaust heat recovery, making it significantly more efficient than previous marine gas turbines, especially at low and medium load. The combination of greater efficiency and high fuel capacity gives an endurance of at . High power density and the hydrodynamic efficiency of a longer hull form allow high speeds to be sustained. It has been reported that "Daring" reached her design speed of in 70 seconds and achieved a speed of in 120 seconds during sea trials in August 2007.