With the car transferring power to the ground through a single-clutch mid-rear transaxle, the Vanquish doesn't cycle through gear ratios with quite as much impact as a car with a dual-clutch automatic manual transmission, the Ferrari V12, for instance, which also enjoys a 165-hp advantage.
WSJ: 2014 Aston Martin Vanquish Review: No, Mr. Bond, I Expect You to