Today’s Special


Audio Technology Used to Benefit Fuel Economy

By Michael Silbergleid

AutomotiveDiscovery.com reports that engineers at General Motors lowered the Terrains 6-speed transmission by enabling the Ecotec 2.4L four-cylinder engine to run at a lower RPM torque.  While driving, the driver is able to activate the “Eco mode” by a simple click of a button the cars console.  This lets the torque converter clutch engage at a lower engine speed and save on gas.  While in “Eco mode” a low-frequency noise is created from the engine running at the lower speed.

Noise-cancellation technology is being employed by GMC to counteract the bothersome low-frequency noise created when the vehicle is in “Eco mode.”  The GMC Terrain noise-cancellation system relies on two microphones embedded in the headliner.  When these microphones detect the low-frequency hum they generate a frequency that creates sound waves through the audio speakers and sub-woofer that offsets the noise being created by the low RPM mode. 

“The use of active noise cancellation for fuel economy benefit on Terrain is among the first at GM,” said Paul Beaker, program engineering manager for GMC Terrain. “It has strong potential for implementation on other four-cylinder vehicle programs.”