2011 Chevy Equinox

There are many ways of making a vehicle more fuel efficient. Improvements in engine technology, materials, rolling resistance and aerodynamics can all contribute towards making a car easier on gas than its predecessor. How about making it quieter? You may think making a car quieter at speed might involve more sound-damping material and therefore more weight, but General Motors has used techniques often found in sound-cancelling headphones improve the economy of the Chevrolet Equinox. Engines are generally most efficient at quite low engine speeds, but this can often result in unpleasant...