The Chevrolet Camaro won't be hitting the market until early 2009, about six months after Chrysler launches its Challenger.

GM isn't saying yet what engine options the Camaro will initially have, but, like the Dodge Challenger and Ford Mustang, it will ultimately be available with smaller V6s, not just big V8s.

"It's not just a V8 muscle car," said Camaro marketing manager John Fitzpatrick "It's not just about straight-line power"

The big V8 engines will be the headline feature just as they always have been for cars like this. But GM expects expects most Camaros it sells will be fitted with V6 engines. While buyers might like its performance-car looks, many won't really want the performance car fuel-economy or the performance car insurance premiums.

So the damage to GM's overall fuel economy numbers will be relatively small because cost considerations will keep most customers out of the thirstiest versions of these cars. In reality, most Camaros and Challengers sold will probably have fuel economy similar to other cars their size.