Performance fans have access to more power than ever -- at least for now

2011 Ford Mustang: 305 horsepower (Ford)

"Green" vehicles may be stealing the spotlight these days, but fans of performance cars are reaping rewards like never before.

Consider the 2011 Ford Mustang. It has a new 3.7-liter V6 that produces 305 horsepower, only 10 less than the V8 in the 2010 Mustang GT. A step up, the 2011 GT's V8 generates 412 hp. For the ultimate in performance, there's the Shelby GT500, which also gets a new mill: an aluminum-block, 5.4-liter supercharged V8 rated at 550 hp.

In other words, the Mustang's V6 produces as much horsepower as a V8 engine did a decade ago, while the V8 generates about as much horsepower as a NASCAR Sprint Cup car running at Daytona.

It's a similar story for the Chevrolet Camaro (304-hp V6 or 426-hp V8) and the Dodge Challenger (250-hp V6, 372-hp V8 or a 425-hp Hemi).

Foreign automakers have been turning up the juice as well. The Mercedes-Benz S63 offers 604 hp, and the E63 comes with 518 horses. Jaguar's XJ-R, with 510 hp, and the BMW M3's 420 hp also dish up enough tire-scrubbing potential to make performance buyers giddy with delight.

Although some of the imported cars carry six-figure price tags, the cost of a domestic car with a V6 rivals that of a typical midsize sedan.

Even small cars have gotten into the act. The Honda Civic Si has a 197-hp engine -- almost as much power as a 1986 Porsche 911 Carrera.

It's easy to fall under the spell of this much motorized muscle, especially when its cost is so reasonable. But you don't have to be a soothsayer to realize that we've likely reached a performance crescendo, one similar to that of 1970, just before killer insurance rates and new emission regulations killed performance cars the first time around.

Once again, it's the government that will be seen as spoiling the party for enthusiasts.

New EPA rules dictate that an auto manufacturer's fleet average 35 mpg by the 2020 model year. In a mere decade, automaker fleets need to produce enough cars that yield ultra-high mileage to offset the other cars in their lineups.

Some V8s now have as much power as a NASCAR Sprint Cup racecar. (Nick Wass / The Associated Press)

That means a rush toward electric cars and gas-electric hybrids whose 150 mpg will more than offset a thirsty V8, at least for now.

Once ultra-efficient cars become the norm, however, manufacturers will find a way to make them entertainingly fast. The V8 engine may be on borrowed time, but performance cars are not.

Proof came at the Geneva Motor Show in March, where Porsche showed a gas-electric hybrid sports car with a zero-to-62 mph time of 3.2 seconds, top speed of 198 mph and fuel-economy rating of 78 mpg.

Going fast while reducing dependence on foreign oil? Sounds like rewards for everyone.