Bringing down the noise

To reduce noise and vibration from a cylinder-on-demand engine in three-cylinder mode, engineers at Honda R&D have developed an active engine mount system.

Automakers are increasingly employing cylinder deactivation to help improve the fuel economy achieved by their cars, trucks, and SUVs. Honda's version of the technology, called Variable Cylinder Management (VCM), will be featured on the new 2005 Odyssey minivan (shown below) being launched this month as well as on the 2005 Accord Hybrid scheduled to go on sale later this year (The Honda Inspire, a Japanese domestic model, was the first to employ the technology.) VCM enhances efficiency by deactivating three of the V6 engine's cylinders during cruising and deceleration, with no impact on vehicle performance or passenger comfort.

Contributing to passenger comfort, particularly when the engine is operating in three cylinder mode, is an Active Control Engine Mount (ACM) system, which has been developed as a noise and vibration (NV) countermeasure technology. Before being fitted to the production vehicles, this system, along with active noise control (ANC) technology, was tested on a Honda Accord powered by a 30-L V6 cylinder-on-demand engine.