"When you're attempting to build the world's greatest 2+2 sports car - and that's certainly the goal for the DB9 - there really is no substitute for a V12," says Aston Martin's Chief Powertrain Engineer Brian Fitzsimons. "Aston Martin's V12 is acknowledged as one of the best in the world, so was a very good starting point."
The engine is developed from the V12 used in the Vanquish. The advanced quad-cam 48-valve engine has been designed by Aston Martin engineers in partnership with Ford's RVT (Research and Vehicle Technology), and is unique to Aston Martin.
The crankshaft is new, as are the camshafts, inlet and exhaust manifolds, the lubrication system and engine management. The result is more low-down torque and a more seamless power delivery. Maximum power is 450bhp and maximum torque 570Nm. Even more impressive, 80 per cent of that maximum torque is available at only 1500rpm.
"This car will overtake in any gear, at any revs, more or less any time. It really is that good," says Fitzsimons.
Comparing the Vanquish's engine to that of the DB9, Fitzsimons comments: "The Vanquish offers more ultimate performance, the DB9 has more torque over a wider rev range," says Fitzsimons.
In the new DB9, the V12 - which is a significant 11.8kgs (26lb) lighter than the Vanquish V12 - has been fitted as far back and as low as possible, to assist agility and handling. This helps the DB9 achieve its perfect 50:50 weight distribution.
Engine note is also very important to the driving experience. "The Aston V12 engine has been described as having the best sound in the world," says Brian Fitzsimons. "We spent a great deal of time getting the 'music' of the DB9 just right."
The DB9 is fitted with a rear transaxle to help achieve the ideal 50:50 weight distribution. The front mid-mounted engine is connected to the rear gearbox by a cast aluminium torque tube, inside which is a carbon fibre drive shaft. The use of carbon fibre prevents any flex and ensures low rotational inertia, improving response and cutting both noise and vibration.
Two transmissions are offered: a six-speed ZF automatic gearbox and a new six-speed Graziano manual gearbox. The ZF automatic used in the Aston Martin DB9 is particularly innovative. The DB9 is one of the first cars in the world to use a shift-by-wire automatic gearchange. The conventional PRNDL gear lever has been replaced by a system of buttons that select park, reverse, drive or neutral.
"It's easy to use and gets rid of the clutter associated with the automatic gear lever on the centre console," says David King.
Those choosing the ZF automatic can drive the car in full auto mode, or can change gear manually using the paddle shifts. The paddles are made from lightweight magnesium and are directly behind the steering wheel, at the 10-to-two position. They allow instant Touchtronic gearchanging.