Run on 8-cylinders when you need power, 4 when cruising.

(from a DaimlerChrylser press release)

"The Chrysler Group Multi-Displacement System (MDS) seamlessly alternates between smooth, high fuel economy four-cylinder mode when less power is needed, and V-8 mode when more power from the 5.7L HEMI engine is in demand," said Eric Ridenour, Executive Vice President Product Development, Chrysler Group. "This optimizes fuel economy when V-8 power is not needed, without sacrificing vehicle performance—2005 Chrysler 300C and Dodge Magnum RT owners will get the maximum benefit without any compromises."

The HEMI-powered 2005 Jeep Grand Cherokee will come equipped with MDS as standard equipment. Owners of the Chrysler 300, Dodge Magnum and Jeep Grand Cherokee will receive the powerful benefit of the HEMI engine with the fuel economy that they would only expect from a smaller, less powerful engine. "The MDS was part of the engine's original design," said Bob Lee, Vice President Powertrain Product Team, Chrysler Group. "This resulted in a cylinder-deactivation system that is elegantly simple and completely integrated into the engine design. The benefits are fewer parts, maximum reliability and lower cost."

The HEMI engine with MDS has completed over 6.5 million customer-equivalent miles through Chrysler Group's development and durability testing. It is covered by the 7-Year/70,000-mile Limited Powertrain warranty.

The system deactivates the valve lifters. This keeps the valves in four cylinders closed, and there is no combustion. In addition to stopping combustion, energy is not lost by pumping air through these cylinders.

Customers will experience estimated fuel economy gains of up to 20 percent under various driving conditions, and a projected 10 percent aggregate improvement. Improved fuel economy is realized without any change in customer experience—drivers will receive the benefit without changing their driving habits and without compromising style, comfort or convenience.