Could have a biturbo 3.6-liter V6 engine

The Chevrolet Camaro Z/28 has been spied undergoing testing at the General Motors Milford Proving Grounds.

Set to join the recently introduced Camaro ZL1 Coupe and ZL1 Convertible, the next-generation Z/28 is heavily disguised but will likely feature a more aggressive body kit.  The spy photos don't reveal much but the last generation model had a front splitter, a ventilated hood, and a large rear spoiler.  The prototype also boasts lightweight alloy wheels and a four-tailpipe sports exhaust system.

The sporty styling will likely continue in the cabin as the model is expected to have Recaro sport seats. The outgoing Z/28 also had a number of weight saving measures including lightweight rear seats, a minimalistic audio system, and an air condition system that was optional.

Engine options remain unconfirmed but the model will reportedly use a 3.6-liter biturbo V6.  If the rumors pan out, the purists will likely protest as its predecessor had a naturally-aspirated 7.0-liter V8 engine that produced 505 horsepower and 481 pound-feet of torque.

Regardless of what's under the hood, the new Z/28 will likely come equipped with a limited-slip differential and a sport-tuned suspension that has new springs and special anti-roll bars.  Drivers can also expect to find a high-performance cooling system and Brembo carbon-ceramic brakes.

Gallery: Chevy Camaro Z/28 spy photos