DETROIT – Ford is cranking up the horsepower on the 2011 Mustang as it tries to win back muscle-car sales from its archrival, the Chevrolet Camaro.

Ford Motor Co. introduced a 305-horsepower V-6 engine for the Mustang last week at the Los Angeles Auto Show. For anyone counting, that’s one horse more than the Camaro’s V-6, which clocks in at 304 horsepower. And it’s far more powerful than the 210-horsepower V-6 on the 2010 Mustang.

Ford also promises better fuel economy from the 3.7-liter, Duratec all-aluminum engine, with 30 miles a gallon on the highway to Camaro’s 29.

It’s a bid to win back attention from the Camaro, which went on sale in the spring and has sold at a blistering pace despite the struggling economy.

Camaro sales might even outpace Mustang this year, something that hasn’t happened since 1985.

Through October, Ford sold 56,469 Mustangs, topping Camaro by 9,136 vehicles.

But the momentum is on the Camaro’s side. In October, General Motors Co. sold 8,082 Camaros, while Ford sold 4,789 Mustangs. And sales of the Mustang – which was reintroduced in 2005 – fell 32 percent during the first nine months of the year.

Mustang and Camaro have been going at it since 1966, when the Camaro was first introduced two years after the Mustang. Nipping at their heels was the Dodge Challenger, which was first introduced in 1970.

A retro Challenger released last year has also been a juggernaut, with sales up 85 percent to 21,276 through October. The Challenger’s V-6 gets 250 horsepower and 25 miles to the gallon. All three cars start at $22,000.

Muscle cars have been a bright spot in an otherwise dismal year for U.S. auto sales, which have fallen to their lowest level in decades.

Scott Oldham, editor in chief of Edmunds.com’s product-focused Insideline.com Web site, said it’s unclear how long the sales surge can last for the Camaro. Consumers are fickle, and historically, it’s been difficult for a novelty car to maintain its popularity over a long period of time, he said.

Yet healthy sales for muscle cars shows that the auto market is still a diverse place, Oldham said.

Attention may be focused on fuel economy and electric vehicles, but for some buyers it’s still all about the horsepower.

“The Camaro proves that there is a demand for sexy vehicles that provide a lot of power for the dollar and that companies can have success down the road both ways,” he said.

“Nobody is buying a Camaro for the mileage. They buy a Camaro because they want it,” Oldham said. “They want to be seen in it. They want to walk out to their driveway and look at it, and they want to put their foot down on the gas pedal.”