LAS VEGAS – The Fiat 500 minicar had a rocky first year in the U.S. There were dealership snafus, supply shortages, a management shakeup and a year-end sales tally of 19,769 vehicles, well short of CEO Sergio Marchionne’s stated goal of 50,000 units.

But 2012 is shaping up to be better: Dealer and supply issues are being addressed, the Gucci variant of the 500 is sold out and Tim Kuniskis, who became head of Fiat in North America in November, has a clear vision for continuing the brand’s U.S. return after a 28-year absence.

Most important, the minicar had what Kuniskis describes as a “great January,” notching 1,911 deliveries, followed by a record-high 3,227 sales in February.

Giving the 500 a massive boost – up to 18 psi (1.2 bar), to be precise – is the turbocharged Abarth edition, which pays tribute to Italian motorsports legend Karl Abarth. He survived a 1939 wreck during a motorcycle race in Yugoslavia and 10 years later founded a company dedicated to aftermarket components intended for motorsports, particularly exhaust systems.

Which explains why the 500 Abarth (pronounced AH-bart, with a silent “H”) makes such a joyous ruckus when the key is turned. It’s oddly amusing to hear the deep, guttural Harley Davidson-esque sound emanating from the tailpipe of this diminutive car that ostensibly seats four, but only two comfortably.

Abarth designed what Fiat calls the “concentric double-tip dual exhaust system” that incorporates a unique array of baffles within the resonator to minimize restrictions for maximum power. At idle, the exhaust tone is intoxicating, but the sound on the highway might get tiresome.

The only time the exhaust goes unnoticed is on the race track, when the Pirelli Z-rated tires pilot the car through tight twists and along the way squeal a chorus that easily drowns out any soundtrack from the engine.

From bumper to bumper, nearly every aspect of the base 500 gets special treatment so the Abarth can accommodate weekend club racers. The sheet metal, however, carries over unchanged.

Starting under the hood, the MultiAir SOHC 1.4L gasoline 4-cyl. produced in Dundee, MI, is mated to a turbocharger that boosts output to 160 hp and 170 lb.-ft. (230 Nm) of torque, which represents increases of 59% and 70%, respectively, compared with the base 500.

Twin intercoolers provide denser air charge to the combustion chambers, which results in more power and prevents engine knock.

The turbocharger, combined with the exhaust note, transforms the drive experience from one that is ho-hum in the base car into a semi-exotic joy ride that pays tribute to Italy’s love for motorsports.

Not to be overlooked is the Fiat-designed ground-breaking MultiAir cylinder head, which delivers infinitely variable control of the intake valves through a remarkably intelligent electrohydraulic process that determines, cylinder by cylinder and stroke by stroke, the precise amount of air needed for combustion based on the driver’s throttle inputs.

When the driver backs off, the system adjusts valve-opening events for maximum efficiency to conserve fuel. Fiat testing suggests the system improves fuel efficiency 7.5% based on the U.S. cycle and 10% in the European cycle.

Although the turbocharged port-injection 1.4L represents a huge improvement for the 500, turbo lag results in relatively thin low-end torque, as very little happens below 2,500 rpm. When the torque does kicks in, it does so furiously.

Surprisingly, the 500 Abarth exhibits very little torque steer, which often hinders front-wheel-drive turbocharged small cars. It helps that 64% of the 2,533-lb. (1,151-kg) curb weight is biased toward the front axle.

The 500 Abarth’s electric power steering is acutely responsive to aggressive inputs, thanks to a higher steering-gear ratio of 15.1:1 (compared with 16.3:1 for the base 500). The result is a car that revels in every second it spends on the track, without feeling overly darty during casual driving.

Fiat offered journalists ample time on a 3.1-mile (5-km) road course at Spring Mountain Motor Resort, located about an hour from here and delivering 19 curves and more than a few unexpectedly tricky dips.

A car with an elevated seating position and roofline also has a high center of gravity and, one would think, should not handle that well, given its short wheelbase.

To the contrary. Even when pushed to the limits in tight corners on the track, the 500 Abarth remains amazingly stable, thanks to chassis and suspension re-engineering.

Helping the cause are a beefier rear suspension, lowered ride height, larger brakes, wider tires and Abarth-designed cast-iron lower control arms up front for improved lateral stiffness. Unique MacPherson front struts provide a spring rate that is 40% stiffer than that used on the 500 Sport.

New dual-valve Frequency Selective Damping front shocks from Koni replace the standard twin-tube units and provide maximum grip while actively filtering out high-frequency suspension inputs from uneven road surfaces, for improved comfort.

Electronic stability control can be turned off but is better left on at the track, especially because ESC enables the transfer of torque from a front wheel that slips to the one that grips.

Inside, the most significant upgrade is the race-inspired and heavily bolstered front seats, available in red or black with bold accent stitching.

As for complaints, there are a few. For instance, Fiat’s C510 5-speed manual transmission really needs a sixth gear for highway driving. A 125-mile (201-km) loop from downtown through the desert to the track and back yields middling fuel economy of 28.4 mpg (8.3 L/100 km), according to the vehicle trip computer. Even under journalists’ heavy feet, a 1.4L turbo in a 2,533-lb. (1,151-kg) package should do better.

An automatic transmission is not available in the 500 Abarth. And even though Fiat has a dual-clutch automatic transmission, there is no plan to use it in this application, sadly. The issue is space: neither the DCT nor a 6-speed manual can fit in the cramped engine bay, Chrysler engineers say.

Within the interior, two complaints are not unique to the Abarth. First, the audio controls are located toward the driver’s side of the center stack, dangerously close to both the steering wheel and gear shifter in the event the passenger wants more volume.

Second, both visors are comically short when positioned to the side, leaving occupants with zero shade from the hot sun. How difficult would it be to add a plastic insert that extends the visor in the side position?

Even with these hiccups, the Abarth is the shining star in the 500 lineup and the one to own, with a reasonable base price of $22,000. Fully tricked out, Fiat executives say the car should go for about $25,000. At that price, the Abarth might outsell the base 500.

Key competitors in this unique niche include the Mini Cooper S and Volkswagen GTI, both of which boast slightly higher power-to-weight ratios.

But neither of those cars bears the bold red 3-tier perforated Abarth racing stripe that resonates with tuners both young and old. And clever, scintillating commercials featuring European super model Catrinel Menghia and TV bad-boy Charlie Sheen are drawing attention from the intended audience.

The 500 Abarth arrives just in time for an anticipated spike in fuel prices, which actually might help this pint-sized pony car.

At some point, cars like the 500 Abarth will become the muscle cars of the future.

tmurphy@wardsauto.com

’12 Fiat 500 Abarth
Vehicle type Front-wheel-drive, front-engine 2+2 coupe
Engine 1.4L turbocharged MultiAir port-injection SOHC 4-cyl. with cast-iron block/aluminum head
Power (SAE net) 160 hp @ 5,500 rpm
Torque 170 lb.-ft. (230 Nm) @ 2,500-4,000 rpm ext
Bore x stroke (mm) 72 x 84
Compression ratio 9.8:1
Transmission 5-speed manual
Wheelbase 90.6 ins. (230 cm)
Overall length 144.4 ins. (367 cm)
Overall width 64.1 ins. (163 cm)
Overall height 59.2 ins. (150 cm)
Curb weight 2,533 lbs. (1,151 kg)
Base price $22,000
Fuel economy 28/34 mpg (11.9-6.9 L/100 km)
Competition Volkswagen GTI, Mini Cooper S, Mazda3
Pros Cons
Shockingly good on track Who makes 5-speeds anymore?
MultiAir is magical and cool Fuel economy should be better
Sport seats worth the premium Why call it a back seat?