10 Fastest cars under $50,000

The 2012 Porsche 911 Carrera S can churn out nearly 400 horsepower, but it’ll set you back close to $100,000. Want to feel just as much power for half the money? Buy a Ford Shelby GT500.

Thanks to improved engine technologies that produce higher horsepower, and lighter materials that lower a car’s curb weight, the latest generation of relatively affordable, mass-market sports cars can go as fast if not faster than many of the fancier vehicles blazing down the highway, according to auto experts at Edmunds.com.

Quantifying speed can be tricky. Automakers have been steering clear of advertising a car’s top speed for legal reasons, explains Bruce Harrison, a research director at IHS Automotive. So what about zero-to-60 times? That measures acceleration, and the significance of that number is waning, some experts say.

“The numbers are getting so close and so good,” says Edmunds analyst Ivan Drury. “The fact that the Toyota Camry can go from zero to 60 mph in 6.5 seconds is kind of mind-blowing compared to the muscle cars in the ’60s doing the same time,” he says.

So what’s the best way to determine a car’s speed? Horsepower and weight: the lower the ratio of power to curb weight, the faster the car, experts say. Based on that metric, researchers at Edmunds.com helped us determine the fastest cars under $50,000.

One surprise: U.S. automakers sweep the top five spots.

A big part of why horsepower, and therefore speed, has improved so drastically in recent years is that stability control, antilock brakes, and even the more complicated details of fuel injection, variable valve timing and turbocharging or supercharging are now being facilitated by computers, says Harrison of IHS.

“There are so many other factors that go into it, how big are the brakes, how many speed transmission is it, what gear ratio is in the vehicle, what kind of suspension helps it get around a corner. There are so many different variables that go into it,” Harrison says.

For instance, Ford says it uses electric power assisted steering instead of engine-driven hydraulic pumps that use up a lot of power. “These changes also enable better engine performance because more of the power output is directed to the wheels,” says Truett of Ford.

But cars are getting faster across the board, across all brands as well as price ranges.

“I wouldn’t say that advances are impacting low-priced cars more than high-priced vehicles, but I do think that, as economies of scale kick in, it’s easier to put some of the more advanced technologies on the less expensive vehicles,” Harrison says.

#10 2012 Subaru Impreza WRX STI
Horsepower: 305
Power-Curb Weight Ratio: 11.1
Price: $36,095