The audi 12 cylinder engine is not really a V12, it consist of two VR6 engines in V-shape. Actually it is a W12 engine, and that is how it is called. The W12. Audi choose for a W12 since a V12 does not fit in the A8 engine compartment with the quattro drivetrain.
On paper the W12's performance does look good, but I have some hard feelings on reliability with this engine. First of all, the cranckshaft is very short so all the cranckshaft bearings and the piston rod bearings must be smaller than for a normal V12 engine. With that high power output I have some hard feelings about their longevity.
Second, the heat build up in this engine, When the VR6 was introduced in 1991, a lot of engines suffered from an overheated 6th cylinder until 1993 when VAG solved the problem. The main cause was the thermal stress and I know of some people who had to rebuild their engines becuase of this. With a W12 and 420hp, things can only be much worse.
The VR6 is a marvellous piece of engineering, and actually is the best V6 which exist today. It combines the smoothness of the inline 6 cylinder and the small size of a V6 engine. It is no wider than a 4 cylinder engine either. But that has created some big technical problems to solve (mechanical and thermal stress). I can only hpe for Audi that they do not have these kind of problems with their W12 engine.
With best regards,
Raymond
|