510 bhp (380 kW; 517 PS) and 620 N·m (457 lb·ft) respectively for the 2013 model year.
The Aston Martin DB9 was initially launched equipped with a 5.9-litre V12 engine, already being used in the V12 Vanquish. The engine produced 570 N·m (420 lb·ft) of torque at 5,000 rpm and a maximum power of 450 bhp (336 kW; 456 PS) at 6,000 rpm. The DB9 can accelerate from 0 to 60 mph (97 km/h) in 4.7 seconds and has a top speed of 186 mph (299 km/h). The engine largely sits behind the front-axle line to improve weight distribution. The 2009 model year DB9 featured an increase of engine power and torque, as the V12 now produced 470 bhp (350 kW; 477 PS) and 600 N·m (443 lb·ft), resulting in a power to weight ratio of 267 bhp per tonne, an increase of 11 bhp per tonne over the previous model. The top speed increased to 190 mph (306 km/h) and the 0 to 60 mph (97 km/h) time improved by 0.1 seconds to 4.6 seconds for the manual version of the car. Changes to the engine for the 2013 model year DB9 increased the horsepower to 510 bhp (380 kW; 517 PS) and torque to 620 N·m (457 lb·ft). The car's 0 to 60 mph (97 km/h) time decreased to 4.5 seconds and the new top speed is 183 mph (295 km/h). The DB9 can be equipped with either a six-speed conventional manual gearbox from Graziano or a six-speed ZF 'Touchtronic' automatic gearbox featuring paddle-operated semi-automatic mode. The automatic gearbox increases the 0 to 60 mph (97 km/h) time to 4.9 seconds, though the top speed remains the same. The 2009 model year featured a revised 'Touchtronic 2' gearbox, which offered faster gear shifts thanks to a new valve box and integrated transmission controls. The 0 to 60 mph (97 km/h) time decreased to 4.6 seconds, an improvement of 0.3 seconds.The gearbox is rear-mounted and is driven by a carbon-fiber tail shaft inside a cast aluminium torque tube.