As hard as it is for some to believe, not everyone needs or wants eight cylinders. In fact, automakers have started to flock to V6's to power performance vehicles. The new Hyundai Genesis Coupe has a 300HP V6, as does the concept Suzuki Kizashi 3. A well-built V6 can offer similar power, lower weight and better fuel economy than a V8. But a muscle car is a muscle car because of its V8 muscle, right?

Maybe not. The new V6-powered Dodge Challenger gets 250 horsepower, which is 20 more horsepower than the V8 standard on the original Challenger, while getting 25 mpg. The latest Shelby Terlingua Racing Stangs have historic muscle car DNA and feature a V6. So does the Shelby CS6. Given rising fuel costs, overall savings and the improvement of V6's would you buy a V6 muscle car?