This muscle car scored highest in key safety test

America's love affair with muscle cars is growing stronger, but a new report gave these vehicles mixed grades when it comes to protecting passengers from one of the deadliest and most common collisions.

The Insurance Institute for Highway Safety ran the Chevy (GM) Camaro, Ford (F) Mustang and Dodge (FCA-IT) Challenger through a series of crash tests to see how their safety stacks up against their power. While the institute said the overall results were encouraging, none of the models performed well enough to earn a "top safety pick" rating.

The mixed findings come as Americans are purchasing more of these vehicles, which are being built with even more power.

"We are pleased with the fact that the results weren't bad," IIHS President Adrian Lund said. "We haven't tested this group before and you never know what automakers are doing with vehicles that you haven't tested."

In the "good news" column, none of the muscle cars earned a "poor" rating in any of the crash tests. And when it came to the side impact and front moderate overlap crash tests, all three models earned the top evaluation of "good."

However, results were mixed for the small overlap front crash test. This collision replicates what happens when the front corner of a vehicle slams into another vehicle or object at 40 mph. It is one of the most common and deadliest crashes.

According to the IIHS, only the Chevy Camaro earned a rating of "good" on that test. It did better than the Ford Mustang, which scored as "acceptable." The Dodge Challenger's performance was called "marginal."

"We are concerned about the 'marginal' performance of the Challenger in the small overlap frontal crash test," Lund said. "Coupled with only an 'acceptable' rating in roof strength, our concern there is these types of vehicles tend to be involved in a lot of single-vehicle crashes and single-vehicle crashes with rollovers."

Fiat Chrysler, the parent company of Dodge, told CNBC in a statement, "No single test determines overall vehicle safety. FCA U.S. vehicles meet or exceed all applicable government safety requirements. FCA U.S. urges all motorists to follow all applicable traffic laws and maintain control of their vehicles accordingly."

All three cars meet federal motor vehicle safety standards. They were not given an overall rating by IIHS.

The tests come at a time when the Big Three U.S. automakers are pushing muscle cars that are more powerful than ever before.

Earlier this year, GM executive Mark Reuss took reporters for test drives in the new Chevy Camaro ZL1, which boasts 640 horsepower.

"Putting that much power to the ground and controlling it and making someone be able to feel like a professional driver, even though they may not be, is magical," he said.

Ford's 2016 Mustang Shelby GT350 has a whopping 526 horsepower, while Dodge's 2016 Challenger SRT Hellcat comes with 707 horsepower.

With gas selling for less $3 a gallon in much of the country, muscle car sales are roaring. Last year, the Big Three sold more than a quarter million of them in the U.S. Since 2009, sales are up 72 percent.

That appeal is not lost on Lund.

"It is all the more important that they [muscle cars] have state-of-the-art protection for the crashes they are going to get in, because their crashes are going to be faster," he said.

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