But for all its comfort, engineers did sacrifice a few components in the quest for lower weight and higher performance. Seat side bolsters are fixed and more supportive to better hold the driver when cornering and they weigh less. The passenger seat features manual controls, saving the weight of a power-adjust motor, and Chevrolet Corvette Z06's acoustic package is revised to reduce weight and allow more aural feedback of the powertrain.
* Horsepower and torque SAE certified. A new voluntary power and torque certification procedure developed by the SAE Engine Test Code committee was approved March 31, 2005 . This procedure (J2723) ensures fair, accurate ratings for horsepower and torque by allowing manufacturers to certify their engines through third-party witness testing. GM was the first auto manufacturer to begin using the procedure and expects to use it for all newly rated engines in the future.
