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Finally, a muscle car with manners.

When you start the Ford Mustang Shelby GT500 – at least one equipped with the optional navigation system – its angry cobra logo appears on the display in the center console subtitled with a polite “Good Morning,” or “Good Afternoon,” or whatever time of day it is. It’s a gracious gesture that serves to put you off guard, like when a movie hitman offers his mark a cup of espresso before introducing a crowbar to the back of his head.

The GT500 can do that, too.

Don’t let the name fool you. The GT500 now packs 550 horsepower under its vented hood, 10 hp more than last year. That’s enough to make it the most powerful factory-built Mustang ever and the undisputed king of the current crop of American muscle cars. More notable than the 1.8 percent bump in power is that the engineers at Ford’s Special Vehicle Team trimmed 102 pounds from the engine bay by switching to an aluminum block for the supercharged 5.4-liter V8. Eight and a half of those pounds were eliminated by replacing heavy, iron cylinder liners with a thin composite coating chock full of nanoparticles.

Retro it is not.

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The motor as a whole is a beautiful thing to behold, mostly because you can. There’s no pointless plastic cover concealing all of its mechanical goodness. The cold air intake, blue heads and roots-type blower mounted in between them lie naked for all to see. It feels and sounds great, too. Those big, idling cylinders sending a massaging rumble through the seats as they pump out a deep, liquid burble that brings to mind an alien mother ship hovering above.

Rile it up and you'll encounter power everywhere. You have to try – hard – not to spin the wheels in first gear, or even second. You could probably get away with simply using third on up all day long, unless you pull onto a drag strip. There, you’ll want to take full advantage of what the 6-speed manual transmission – the only one available – has to offer. If you’re up to the challenge.

The GT500 doesn’t have any sort of electronic launch control. It’s just you, the throttle and the clutch. Luckily the last of those engages nicely - if a bit high in its travel – and helps you get the most out of the 12.4-inch wide rubber at the still relatively light rear of the car. If you like, you can also get some assistance in the shifting department from an “SVT” light in the tachometer that can be set to illuminate at whatever engine speed you think is best for upshifting.

Somewhat incongruously, there’s another light in the speedometer that’s shaped like an upturned arrow and coaches you to change gears for maximum fuel efficiency, which 15 mpg city and 23 mpg highway. That’s just enough to avoid getting hit with a gas guzzler tax. This frugality is the byproduct of that weight cut, a few aerodynamic tweaks and a top gear that can move you down the highway at 80 mph with the engine chugging along under 2,000 rpm. This is a happy place for the GT500.

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As is a road racing course, if you’re driving a GT500 outfitted with the $3,495 performance package, which includes a taller final drive, retuned suspension, staggered 19 and 20-inch forged aluminum wheels wrapped in Goodyear’s latest Eagle F1 SuperCar G:2 rubber and a functional Gurney flap on the rear spoiler. Like all Mustangs, it feels ridiculously light on its feet for a muscle car, particularly one with a solid axle out back. Ford has done amazing things with this ancient technology and, as long as the road surface cooperates, you won’t pine for an independent rear suspension. If not, well at least the seats are comfy.

Handling isn’t technically neutral, but the line between under and oversteer is wide enough that staying on it is a lot easier than walking a tightrope, and the outstanding electric power assisted steering system does more than its fair share to make sure you don’t fall off. That’s not to say that you still can’t make a mess of things. Try to drive it with abandon like a sports car, as I did on the tight track at Raceway Park in New Jersey, and you quickly learn that it’s not. Take the time to figure out its ins and outs, and you’ll find that its limits are impressive. Ford claims the new car is 3 seconds a lap faster than last year’s porker around the company’s own 2.3-mile test track, which extrapolates to more than a 2 minute advantage over 100 miles. That’s an epoch in motorsports.

Until Chevy gets around to doing a Z28 version of the Camaro, this $49,495 beast lives in a bit of a bubble, with no direct competitors to worry about. Yes, that price is about a V6 Mustang more than an entirely adequate Mustang GT, with little to show for it than a lot of extra power, but it’s still the cheapest way to get your hands on 500-plus hp, not to mention a gauge cluster that turns red, white and blue at night.

More often than not, you’ll hear the GT500 compared to the Cadillac CTS-V Coupe, which offers a luxurious interior, useable rear seats, a big trunk and premium features like, let’s see, a telescoping steering wheel (the Mustang doesn't have one). For the extra $15,000 that the Caddy costs, you kind of expect such things. The Shelby makes up for it with its charm. It should be considered an honor to be mentioned in the same breath with such a classy ride.

Just don’t turn your back, or it may be your last.

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2011 Ford Mustang Shelby GT500

Base Price: $49,495

Type: 4-passenger, rear-wheel-drive, 2-door coupe

Engine: 5.4L supercharged V8

Power: 550 hp, 510 lb-ft torque

Transmission: 6-speed manual

MPG: 15 city/23 hwy