You've really got to tell this powertrain what you want, in no uncertain terms. But when you do, when you put your foot into it, the S80 comes to life and provides a spry, sporting drive, the 4.4-liter V8 engine pumping out 311 horsepower and 325 lb. ft. torque. The six-speed transmission offers up smooth and predictable shifts, though the gearing felt pretty short. When you slip it into manual mode and hold the gears for a longer period, the S80's power really come to life, and the driving experience improves significantly. What didn't improve during our week of driving, however, was the S80's fuel efficiency: 16.4 miles per gallon in mixed driving is much too low.