Cadillac officials say the Cien concept “symbolizes Cadillac’s 2002 centennial celebration” because cien is Spanish for 100.
 

The Cien’s styling and construction—using carbon fiber, composites and aluminum—is striking in the same way that the U.S. military’s Stealth aircraft is. The two doors open like scissors, pivoting at the base of the windshield pillars. Setting off the unique look is blue-tinted glass like that used in stylish eyewear.
 

The Cien's 7.5-liter V12 concept powerplant, visible through the car's rear window, generates a whopping 750 horsepower and 450 lb-ft of torque, yet meets the packaging requirements and fuel economy standards of a V8.

"The packaging was probably the biggest challenge we faced, because from the outset we wanted to fit the V12 inside the package of a V8," said Steve Kowalk, GM Powertrain project manager for the Northstar XV12. "We focused on keeping the size down to fit as many different types of vehicles as possible, while maximizing displacement, and then using Displacement on Demand (DOD) to deliver the required power at all times. We also minimized cylinder bore wall thickness to 7 millimeters and used a rear cam drive to create a more compact package and enable a lower hoodline."
 

Engine Like No Other

It’s called the Northstar XV12 concept engine because the all-aluminum, double overhead cam, four-valve V12 uses Northstar structure. But advancements include General Motors Corp.'s DOD technology, which allows the engine to run on six cylinders at times to maximize fuel savings. 

Another notable feature: The Northstar XV12 is designed for 36,000-mile oil-change intervals. It’s accomplished by using improved oil sensors and monitors, reducing oil consumption, improved oil cooling and a larger oil sump capacity.
 

The powerplant is mated to a semi-automatic transmission with racing-style, electronic paddle shifting.