The 2004 Cadillac Sixteen concept car had a 16-cylinder engine.
Cadillac equipped the Sixteen with a naturally aspirated 13.6-liter aluminum V16, using 32 valves and an architecture related to GM’s Generation IV LS small-block family. Cadillac presented the concept in 2003, but it is commonly identified with the 2004 model year in trivia and automotive references.
The engine was designed as a high-performance statement for Cadillac’s flagship concept. It was claimed to produce at least 1,000 horsepower and 1,000 lb-ft of torque without turbocharging or supercharging. Its name directly reflects the cylinder count, although the name also deliberately recalled Cadillac’s historic V-16 luxury cars of the 1930s.
A common mix-up is the engine’s cylinder-deactivation system. When full power was unnecessary, it could shut down either eight or twelve cylinders, allowing the engine to operate on fewer cylinders. That efficiency feature did not change the engine’s underlying configuration: it remained a V16.