GM has revealed the 2012 Buick Regal GS during the weekend, through a series of photos and extensive details ahead of its market launch scheduled for 2011.
Compared to the regular Buick Regal, the GS model comes with a more aggressively styled front end, new 19 inch alloys, trapezoidal exhaust tips and a lower ride height due to the new Interactive Drive Control System which also allows adjustment of the steering sensitivity.
At the interior the 2012 Buick Regal GS features sport seats, a sport steering wheel, aluminium pedals, a premium sound system and Bluetooth connectivity.
In terms of performance the 2012 Buick Regal GS which uses a turbocharged 2.0-litre 4-cylinder engine producing 255 HP and 400 Nm (295 lb-ft) of torque can sprint from 0 to 60 mph in less than 7.0 seconds while top speed was not specified.
The 2012 Buick Regal GS price will be announced sometime net year, and for more official details you check out the press release below. 
GM press release :
    * High-performance midsize sport sedan with 0-60 mph performance of under seven seconds
    * Features exclusive, GS-only high-output version of the Ecotec 2.0L turbo engine with 255 hp and 295 lb.-ft. of torque
    * Buick’s Interactive Drive Control System allows drivers to change the suspension settings and steering sensitivity
    * Exclusive, racing-inspired exterior and interior appointments
    * Goes on sale in the second half of 2011
MIAMI – Buick this evening reveals the production version of the 2012 Regal GS, an even sportier expression of the Regal sport sedan that went on sale earlier this year and has attracted new buyers to the Buick family. Powered by a high-output, exclusive Ecotec 2.0L turbocharged engine mated to a six-speed manual transmission, the GS delivers an estimated 255 horsepower (190 kW) and 295 lb.-ft. of torque for a 0-60 mph performance of less than seven seconds (estimated). Buick’s Interactive Drive Control System is standard on the GS, allowing drivers to customize the driving experience by changing the suspension settings and steering sensitivity between three modes: standard, sport and GS.
“Built on the performance foundation of the Regal, the Regal GS was designed as an even sportier expression of responsive performance and style,” said John Schwegman, vice president of Buick marketing. “The driving experience is powerful and spirited; and the GS represents the next entry in Buick’s product renaissance.” 
The Regal GS will be unveiled this evening at a consumer event in
Miami. It goes on sale in the second half of 2011. Pricing has not yet
been announced.
Product highlights include:

  • Exclusive Ecotec 2.0L turbocharged and intercooled engine
    rated at an estimated 255 horsepower (190 kW) and 295 lb-ft of torque
    (400 Nm)
  • Six-speed manual transmission, with six-speed automatic with Driver Shift Control to be offered later
  • Interactive Drive Control System with GS mode
  • Four-wheel independent system with HiPerStrut front suspension
  • High-performance four-wheel disc brake system with Brembo front calipers
  • Standard 19-inch, 5-Twin Spoke alloy wheels and all-season
    tire and optional 20-inch, 5-Twin Spoke polished alloy wheels with
    performance tires.
SEE ALSO:  Buick concept teased

The exterior design features unique front and rear fascias, with the
front fascia incorporating prominent, vertical air intake slots and
specific grille treatment – with the vertical elements accented in a
satin-metallic finish. The rear fascia has a pair of integrated,
satin-metallic trapezoidal exhaust outlets. Rocker panel extensions and
an integrated rear spoiler are also woven into the design. The GS cuts a
sportier stance, too, with a slightly lower ride height than other
models and aggressive 19-inch, 5-Twin Spoke alloy wheels and all-season
tires (20-inch, 5-Twin Spoke polished alloy wheels with performance
tires are optional).
Inside is a racing-inspired, flat-bottom sport steering wheel and
metal sport pedals, along with leather-appointed 12-way power-adjustable
sport driver and front passenger heated seats, which include four-way
power lumbar. The GS-specific black interior is accented with
satin-finish elements on the instrument panel, steering wheel and
console, while the instrument panel glows white when the driver engages
the GS mode of the Interactive Drive Control System (IDCS).
Standard amenities for the Regal GS include:

  • Passive keyless entry with push-button start
  • Standard XM Satellite Radio with three-month trial service
  • Harmon/Kardon premium 320-watt sound system with nine speakers
  • Bluetooth phone connectivity
  • Leather-wrapped flat-bottom steering wheel with audio controls
  • Leather-appointed sport seating
  • Heated driver and front passenger seats, with 12-way
    adjustable driver and front passenger seats – including four-way lumbar
    adjustment
  • 120-volt accessory power outlet
  • Power windows with express up/down feature in the front and express down in the rear.
  • Front and rear ultrasonic parking assist
  • Bi-xenon HID headlamps.

Turbocharging and HiPerStrut
Power for the Regal GS comes from a high-output version of the Ecotec
2.0L turbocharged DOHC VVT engine with direct injection technology. It
is based on the engine that will be available on Regal CXL later this
year, but the engine and turbocharger are tuned to deliver greater boost
pressure in the GS. The output is rated at 255 horsepower (190 kW) and
295 lb.-ft. of torque (400 Nm). A three-inch-diameter exhaust system
provides reduced back pressure, resulting in higher engine power
Direct injection technology helps the engine deliver more power
through increased efficiency, while maintaining fuel economy and
lowering emissions. That means less fuel is consumed and lower emissions
generated – including a 25-percent drop in cold-start hydrocarbon
emissions. Variable valve timing optimizes power, efficiency and
emissions across the entire rpm band.
“We’ve been combining direct injection and variable valve timing with
boosted engines since 2006, and there’s no question the Regal GS turbo
has the responsiveness and acceleration of a 3.5L V6, while delivering
the fuel economy of a 2.0L four,” said Mike Anderson, Ecotec global
chief engineer and program manager.
The engine is mated to a standard six-speed manual transmission. A six-speed automatic transmission will be available later.
The Regal GS rides on a relatively long wheelbase of 107.8 inches
(2738 mm), which delivers refined, well-balanced vehicle dynamics. It
also features a four-wheel-independent suspension, with a unique High
Performance Strut (HiPerStrut) front suspension design. The HiPerStrut
system helps reduce torque steer and maintain negative camber during
cornering; the driver experiences reduced torque steer, improved grip
and increased cornering power, along with crisper handling, steering
precision and feedback.
The four-link independent rear suspension is designed to minimize
unwanted toe and camber effects during spirited driving maneuvers,
enhancing vehicle stability.  Both front and rear dampers incorporate
active Computer Damping Control (CDC), continuously changing damper
characteristics to maintain optimal vehicle ride control over varying
road surfaces and profiles. More aggressive, performance-oriented
damping characteristics can also be selected by the driver through the
Interactive Driver Control System.
Braking power comes from a large diameter four-wheel disc brake
system featuring Brembo front calipers. A standard, four-channel
anti-lock brake system is tuned to reduce stopping distances over varied
road surfaces and conditions.  An electronic parking brake is actuated
via a center console-mounted control. The Regal GS also features
standard StabiliTrak stability control system with integrated,
full-function traction control.
Interactive Drive Control System
The Regal GS is also equipped with Interactive Drive Control System
(IDCS) chassis technology (also offered on other Regal models with the
2.0L turbo engine). It delivers enhanced vehicle stability and greater
driving safety. The driver selects among three operating modes –
standard, sport and GS – that change the suspension settings, and
steering sensitivity through the variable-effort steering system.
A sophisticated driving mode control module continually monitors
driving style utilizing yaw rate, lateral and longitudinal acceleration,
steering wheel, throttle and vehicle speed. It defines the dynamic
vehicle state, including acceleration, braking and cornering, to
optimize chassis reactions. It also executes all of the IDCS driver
selections. All four dampers are electronically controlled and
continuously adapt within milliseconds to the prevailing road
conditions, vehicle movements and individual driving style.
Selecting GS mode optimizes the car for dynamic driving, tightening
the suspension and steering response. “Standard,” or the default mode,
is the setting for all-around use. The sport mode provides a level of
performance between standard and the GS modes.
About Buick
Buick is a modern luxury brand offering vehicles with sculpted
designs, luxurious interiors with thoughtful personal technologies,
along with responsive-yet-efficient performance. Buick is attracting new
customers with its portfolio of award-winning models, including the
Enclave crossover, LaCrosse sedan and Regal sport sedan. The new Buick
Verano compact sedan and a small crossover will join the portfolio in
the next few years. Buick’s sales continue to increase in North America,
and it remains a best-selling brand in China, with continuing record
growth. Learn more about Buick cars and crossovers at www.buick.com, on Twitter @buick or at www.facebook.com/buick.

SEE ALSO:  Buick Electra E5 unveiled in China

Overview

Models: 2012 Buick Regal GS
Body style / driveline: four-door, five-passenger, front-engine transaxle. Front-wheel drive midsize sedan
Construction: steel body frame integral
(unibody) with front and rear crumple zones; galvanized steel front
fenders, hood, roof, door panels, one-piece bodyside outer panel,
thermal plastic olefin (TPO) bumper fascias
EPA vehicle class: midsize
Manufacturing location: Ontario, Canada (Oshawa)
Key competitors: Acura TSX, Audi A4

Engines

  2.0L DOHC VVT I-4 ECOTEC Turbo High Output
Displacement (cu in / cc): 122 / 1998
Bore and stroke (in / mm): 3.39 x 3.39 / 86 x 86
Block material: cast aluminum
Cylinder head material: cast aluminum
Valvetrain: overhead camshafts, four-valves per cylinder, continuous variable valve timing for intake and exhaust
Ignition system: individual coil-on-plug
Fuel delivery: direct injection with variable high-pressure rail and electronic throttle control
Compression ratio: 9.2:1
Horsepower
(hp / kW @ rpm):
255 / 190 @ 5300 (est.)
Torque (lb-ft / Nm @ rpm) 295 / 400 @ 2500-4000 (est.)
Recommended fuel: premium recommended but not required
Max engine speed: 6350 rpm
Emissions controls: close-coupled catalytic converter; variable valve timing; 58x ignition system; returnless fuel rail; wide-range O2 sensor
Estimated fuel economy
(city / hwy)
19 / 29 (manual)
18 / 28 (automatic)
SEE ALSO:  Buick concept teased

Transmission

  F40-6 Aisin AF40
Type: six-speed speed manual six-speed transverse, electronically controlled, overdrive automatic with torque converter clutch
Gear ratios (:1):    
First 3.92 4.14
Second 2.04 2.37
Third 1.32 1.55
Fourth 0.95 1.15
Fifth 0.76 0.86
Sixth 0.62 0.68
Reverse 3.75 3.39
Final Drive 3.76 3.33

Chassis/Suspension

Front: independent, MacPherson
strut-type with dual-path mountings, specifically tuned coil springs,
direct-acting stabilizer bar (hollow); hydraulic ride bushings;
continuous damping control (Interactive Drive Control System)
Rear: four-link independent rear; hollow stabilizer bar; continuous damping control (IDCS)
Traction control: all-speed using engine torque reduction and brake intervention
Steering type: hydraulic, variable-effort
Steering wheel turns lock-to-lock: 2.68
Turning circle, curb-to-curb (feet / meters): 37.4 / 11.4 (19-inch wheels)
Steering ratio: 15.2:1

Brakes

Type: four-wheel disc w/ABS (w/ESC)
Brake rotor diameter – front
(in / mm):
14.0 / 355 vented; four-piston aluminum Brembo caliper
Brake rotor diameter – rear
(in / mm):
12.4 / 315 vented; single-piston, aluminum caliper

Wheels/Tires

Wheel size and type: 19-inch alloy, 5-Twin Spoke
20-inch polished alloy, 5-Twin Spoke
Tires: Goodyear Eagle RSA P245/40R19
Pirelli P-Zero P255/35-ZR20

Dimensions

Exterior

Wheelbase (in / mm) : 107.8 / 2738
Overall length
(in / mm):
190.2 / 4831
Overall width (in / mm): 73.1 / 1811
Overall height
(in / mm):
58 / 1480
Front track (in / mm): 62.4 / 1585
Rear track (in / mm): 62.5 / 1587

Interior

Seating capacity (front / rear): 2 / 3
Headroom (in / mm): 38.8 / 985 (front)
36.8 / 935 (rear)
Legroom (in / mm): 42.1 / 1069 (front)
37.3 / 947 (rear)
Shoulder room (in / mm): 56.7 / 1440 (front)
54.4 / 1382 (rear)
Hip room (in / mm): 55.4 / 1407 (front)
52.3 / 1328 (rear)
EPA passenger volume
(cu ft / L) :
96.81 / 2741
EPA interior volume (cu ft / L): 111.1 / 3146
Cargo volume (cu ft / L): 14.25 / 403

Capacities

Fuel tank (gal / L): 18.5 / 70
Engine oil (qt / L): 6.3 / 6.0
Curb weight (lb / kg): 3710 /1683
Source: GM