Since the advent of the muscle car in the 1960s, every commercial has mentioned the horsepower under the hood. And these powerful numbers continue to climb with each new innovation in engine technology. Chrysler claims its Dodge Challenger SRT has the possibility of reaching 707 horsepower with its new Hellcat V8 engine, an option making it “the most powerful muscle car ever built.”

Of course, Chrysler says its claim applies when it builds the car, not when it is modified by home mechanics. However, the news of an optional engine with 707 horsepower came as a shock to industry experts. Chrysler had hinted at horsepower above 600. But the Hellcat V8 has significantly more power than its closest competitor.

“I thought we’d reached the point of ridiculous horsepower numbers when the Corvette ZR1 hit in 2009 with 638 horsepower,” Karl Brauer, senior director at the automotive Web site KBB.com, said recently. “Clearly I was off, as the horsepower wars appear to have only just begun.”

But what do these numbers mean? In general terms, the more horsepower, the faster your car goes, with one horsepower being enough to move 550 pounds of weight exactly one foot in one second. The actual performance is influenced by several variables, including the engine’s cylinder bore and stroke and the design of the intake and exhaust. But the takeaway is that the new engine will make the Challenger SRT a very fast car.

While no statistics have been released, the modern muscle car would reach from 0 to 60 mph in just 3.5 seconds. The top speed could potentially reach 202 mph. However, in order for drivers to utilize the full horsepower of the Hellcat V8 engine, they will need a special red key to ‘unlock’ the power. Dealerships should be able to stock the new Challenger SRT, and its optional engine, during the third quarter of 2014.