Cadillac to build V12 sedan based on Sixteen concept

General Motors product boss Robert Lutz has confirmed plans to build a V12 sedan, likely based on the popular Cadillac Sixteen coupe car. The luxury sedan will compete with the Mercedes S-Class and Lexus LS, according to Lutz.

Mr. Lutz said in an interview while visiting England that development is underway by Holden in Australia for the new V12 powerplant that will be used in the range-topping model.

The new V12 is essentially two 60-degree 3.6-liter V6 engines mated to a common crankshaft, according to AutoWeek magazine. Like the 1000 hp V16 Sixteen concept, the V12 Caddy will feature direct injection, cylinder deactivation, and an advanced automatic gearbox to provide reasonable fuel economy and efficiency.

Holden has reportedly built early test mule prototypes on its rear-wheel-drive Zeta platform, which underpins the new Chevy Camaro and Pontiac G8. However, the chassis might only serve as a test bed for the engine.

The engine will have 7.2 liters of displacement with 600 horsepower and 540 pound-feet of torque. It's not known if GM plans to offer lesser versions of the sedan with V8 powerplants, as Mercedes does with its S-Class. In 2003, Lutz said he wanted to develop a Cadillac luxury sedan with three models: V8, a high-performance V8 and a V12.