The first thing that must be pointed out is that contrary to popular belief, this engine is entirely different from the V10 used by the Lamborghini Gallardo. The Lambo engine was designed for high RPMs, while the S6/S8 V10 was put together for high torque and fuel economy.
The 5.2L V10 is built for two different outputs between the S6 and the S8 applications. The S6 receives a version that puts down 435 hp at 7000 rpm and churns out 398 ft-lbs of torque, while the S8’s creates 450 hp at 6800 rpm and also produces 398 ft-lbs of torque. The varying power numbers are achieved through both its exhaust design and tuning, and the differences in output equate to relatively similar power-to-weight ratios for both cars.