The future of sports cars will be writ by nerds. Every day, engineers are wresting more performance from smaller, more efficient powerplants. So who needs a V-8 when you can draw 400 horses or more from a turbocharged six? Anyone who thinks the smooth delivery of torque is a fundamental right of the American man. And anyone whose pulse races at the guttural rumble of a big V-8. "I can promise you that’s a thrill you will never get from a foreign six-cylinder car," says GM’s Mark Damico, a Corvette engine designer. Sadly, V-8s are probably doomed: Fuel-economy standards that will require manufacturers to average 35 mpg by 2020 will limit their use to a dwindling number of models. Instead of listening to the V-8’s symphony, expect to hear more synthetic approximations of it: Everybody from BMW to Porsche to Ford has been electronically augmenting the engine notes of smaller turbocharged engines. But it's not time to cry in your beer just yet: We've arrived at an unexpected golden hour for big-engined American muscle cars. Just as gas prices are hitting decade lows, the Big Three are unleashing the most powerful, most sophisticated V-8s yet. Enjoy them now, before it's too late.