The '''Cadillac Sixteen''' was a [WIKIPEDIA]prototype[/WIKIPEDIA] of a stylish and high performance [WIKIPEDIA]automobile[/WIKIPEDIA] first presented by [WIKIPEDIA]Cadillac[/WIKIPEDIA] in 2003.
The vehicle was equipped with a 32-valve V16 concept engine displacing 13.6 liters (~830 cu. in) and was mated to a four-speed electronically controlled automatic transmission driving the rear wheels. The engine featured fuel-saving Active Fuel Management technology, much improved from its notorious ancestor, debuting in 2004 on some 2005 GM models. On the Sixteen, it would seamlessly shut down twelve cylinders in light driving, eight during strenuous driving, and only awaken the entire engine under full acceleration. With this type of system, the engine was capable of 20 mpg Imperial under normal conditions. The engine was said to produce 1,000 horsepower (750 kW) using no form of forced induction. The car itself weighs about 2,270 kilograms (5,000 lb).
The car was conceptually related to the [WIKIPEDIA]Cadillac V-16[/WIKIPEDIA] of the 1930s. The actual design of the car was a combination of Cadillac's current "Art and Science" design theme and 1967 Cadillac Eldorado cues. Additional original design elements were provided by an in-house design competition led by GM Vice President Robert Lutz. The Sixteen has the Cadillac logo carved out of solid crystal on the steering wheel and a Bulgari clock on the dashboard.
Although the Sixteen fell short (narrowly, by some accounts) of production approval, its legacy is alive in Cadillac's future product planning. The subsequent generation of Cadillac products, particularly the revised CTS, have incorporated elements of the Sixteen's design. A scaled-down version of the car, referred to as the ULS (Ultra Luxury Sedan) or XLS, with a standard V8 and an optional V12, has been rumored for production since 2005 (source), and has neither been confirmed nor denied by General Motors. Though it is unclear how much it will resemble the Sixteen, a new halo model Cadillac is earmarked for 2010 (source). Due to the bankruptcy this new halo vehicle (announced as the XTS concept) has been pushed back even further. See the XTS forum section for more on the XTS.