REDEFINING COMPACT: 2011 CHEVROLET CRUZE SOUND OF SILENCE

By General Motors - Compact cars are rarely associated with very quiet, refined interiors. Chevrolet's engineers developing the 2011 Chevrolet Cruze took that as a challenge: deliver the quietness of a larger, upscale vehicle while maintaining the value and efficiency of a compact.

"Reducing noise is fairly easy if you have the flexibility to add cost or increase weight," said Cruze Performance Manager, Brandon Vivian. "For Cruze, every change had to meet two criteria; it could not increase the Cruze starting price of $16,995 US, and it could not add weight that would jeopardize Cruze's outstanding fuel economy."

To meet their objectives for the U.S. market, engineers developed more than 30 acoustic treatments that mute unwanted engine, road, and wind noise. Here are 10 of the most significant features:

• 500 inches of structural adhesive reduce structural noise and increase body strength
• Seven pints of liquid sound deadener on the cabin floor mute road and friction noise, and weigh 30 percent less than conventional sound-deadening materials
• A five-millimeter, acoustic-laminated windshield quiets wind noise
• Triple seals for all four doors block wind and road noise
• 30 "Snickers bars" of expandable, sound-blocking baffles in the roofline and window frames quiet noise transmitted around the door openings
• The 26- x 50-inch hood liner features acoustic materials that mute engine noise
• Two sound-absorbing mats on both sides of the front-of-dash panel isolate engine noise, and save three kilograms of weight by using lightweight materials
• A 15-millimeter-thick mat in the spare-tire well absorbs road noise
• Four wheel-well liners, backed with textile material, block tire noise
• A five-layer headliner muffles cabin noise

The quietness of the Cruze illustrates how addressing one sound often brings less-noticeable noises to the surface.

"Every noise masks other, quieter sounds," Vivian said. "For example, reducing a wind whistle on the highway can uncover a tire rumble on coarse roads. With Cruze, we recently added a dampener to the fuel line, because the interior is so quiet that we could hear fuel flowing through the line."

It seems that the engineering team may have hit their mark. After driving the Cruze, MotorWeek's John Davis wrote, "the ride was not only free of vibration, it was big-car quiet."

DriverSide.com's Alison Lakin concurred, writing "Chevy engineers worked hard to improve sound damping in the car, and it has clearly paid off. The Cruze cabin reaches levels of luxury car quietness. Seriously."