Frankly, this isn't the Ford we used to know. With the venerable Mustang coming off a host of big changes just last year, including updated styling, a higher-quality interior and new features, we would have thought nothing would change for the 2011 Mustang. Old Ford would have declared this good enough and kicked back on the porch with a beer in hand. But today's Ford, the one that's been building impressive cars like the Flex and Fusion, has reloaded yet again, and for 2011 it's targeted the 2010 'Stang's primary weakness: powertrains.

We'll start with the V6. No longer is it a woefully underachieving lump that hadn't changed much since the 1990s. The 2011 Ford Mustang's new 3.7-liter V6 now has all-aluminum construction, dual overhead camshafts and variable valve timing. It's enough to crank out 305 hp, or just 10 hp less than last year's V8. Torque is up by 40 pound-feet as well, to give you 280 lb-ft; that screeching sound you hear is a Mustang V6 actually doing a respectable burnout.

Power is still sent to the rear wheels, of course, but this time it's channeled through either a six-speed manual transmission or a six-speed automatic. The extra gears help the Mustang V6 earn a laudable 31 mpg highway EPA fuel economy estimate. This year's V8 has been given a jolt of adrenaline as well. Bumped up in displacement to 5.0 liters, it has four valves per cylinder and dual overhead cams. Peak output is a rip-roaring 412 hp and 390 lb-ft of torque. Both transmissions for the V8-powered Mustang GT (manual and automatic) are similarly upgraded to six-speed units.

Of course, there is still room for improvement. The Mustang is still rocking 1985 with its live-axle rear suspension, for instance, and we would be remiss if we didn't point out that these new engines have raised the Mustang's price by about a grand. Even so, it seems money very well spent. The 2011 Chevrolet Camaro still takes top honors for dramatic styling, and the 2011 Dodge Challenger is surprisingly lovable in an old-school muscle car sort of way. But if you're looking for the best all-around pony car of 2011, you need not look any further than the holistically improved 2011 Ford Mustang.

The 2011 Ford Mustang is available as a coupe or convertible. There are four trim levels: V6, V6 Premium, GT and GT Premium. The base V6 starts with 17-inch alloy wheels, a limited-slip rear differential, keyless entry, side spotter mirrors, cruise control, air-conditioning, full power accessories and a CD audio system with an auxiliary audio jack. The V6 Premium adds upgraded 17-inch wheels, leather upholstery, a power driver seat, Ford's Sync system, color-adjustable gauges, a leather-wrapped steering wheel, upgraded interior trim and a Shaker 500 stereo system.

The V8-powered GT comes with the base V6's features plus 18-inch alloys, a rear spoiler and foglamps. The GT Premium is essentially a GT with different 18-inch wheels and the V6 Premium's roster of features.

Options on the base Mustang V6 include an exterior appearance package and an anti-theft system. The V6 Premium unlocks a slew of packages and options in addition to those available on the base model, including the Pony package and Mustang Club of America Special Edition (both consist of various exterior styling enhancements), the Comfort package (power passenger seat, heated front seats, auto-dimming rearview mirror) and the Electronics package (voice-activated navigation system with travel link, automatic climate control). Also available are remote start, a performance 3.31:1 rear-axle ratio, xenon headlamps, a glass roof, a tonneau cover for convertible models and a back-up camera (which requires the Electronics package). A V6 Performance package (late availability) gets you the suspension and brakes from the GT plus 19-inch wheels, summer tires and a recalibrated stability control system.

The Mustang GT can be outfitted with a Brembo Brake package, which includes more powerful brakes, 19-inch wheels, summer tires and the recalibrated stability control system. Two performance axles (3.55:1 and 3.73:1) are also available. The GT Premium can be had with all the V6 Premium's and GT's options plus an array of 18-inch and 19-inch wheels, a California Special package (more exterior styling variations) and a more powerful Shaker 1000 sound system (not available with the Electronics package).

The Mustang V6 has a new 3.7-liter engine producing 305 hp and 280 lb-ft of torque. The Mustang GT has a new 5.0-liter V8 good for 412 hp and 390 lb-ft of torque. Both have a six-speed manual transmission as standard and a six-speed automatic as optional.

In our performance testing, the GT went from zero to 60 mph in a very quick 4.8 seconds. Fuel economy isn't too shabby, either. The Mustang V6 coupe earns an estimate of 19 mpg city/31 mpg highway with the automatic transmission. With the manual, the highway estimate drops to 29 mpg. The GT has an 18/25 mpg rating with the automatic and 17/26 mpg with the manual.

Antilock four-wheel disc brakes, front-seat side airbags, side spotter mirrors and stability control are standard on all Mustangs. Also standard is Ford's MyKey system, which allows owners to set up driving restrictions for young drivers.

In government crash tests, the 2011 Ford Mustang coupe and convertible earned a top five-star rating for its protection of occupants in frontal and side-impact collisions. In Insurance Institute for Highway Safety testing, the Mustang coupe earned a top score of "Good" in the frontal-offset test and "Acceptable" (the second highest of four ratings) in the side-impact tests. The convertible earned a Good rating for both tests.

In a word, wow. The engine upgrades for the 2011 Ford Mustang have revitalized the car's performance. The V6 model is no longer the butt of rental-fleet jokes, as it now quite quick, particularly when fitted to the slick-shifting manual transmission. The new six-speed automatic is a mixed bag; it upshifts early to maximize fuel economy and lacks shift paddles, but thankfully there's enough power from the V6 to keep the car feeling lively. The new 5.0-liter V8, meanwhile, really hauls the mail, cranking out thumping performance all the way to its 7,000-rpm limit. It sounds great while doing it, too.

The 2011 Mustang's suspension has been retuned, and the car, particularly in GT guise, is tied-down and controlled. Compared to the Camaro and Challenger, the Mustang feels the most nimble, no doubt helped by its lower curb weight. The rear suspension is still a solid rear axle design, but Ford has done a pretty amazing job at minimizing the inherent ride-quality limitations that come along with it. The company has also done well with the 2011 Mustang's new electric-assist power steering, as it feels natural and responsive.

Read our Ford Mustang Long-Term 20,000-Mile Test

The Mustang's cabin retains its characteristic retro design while also boasting respectable materials quality. The result won't fool you into thinking you're driving a luxury coupe, but it's a notably nicer interior than we're used to seeing in a Mustang.

The steering wheel doesn't telescope, but most drivers will still find seating to be comfortable. Major controls are simple to operate and the seats are comfortable. The optional Sync system provides useful voice-integration technology for music and Bluetooth functions. Both the Mustang coupe and the convertible offer seating for four; while average-size adults can fit in back, they'll be a bit cramped. Trunk capacity is a functional 12.3 cubic feet in the coupe and 9.7 in the convertible.