HALF MOON BAY, Calif. — A run along the Pacific Coast Highway, winding south from San Francisco to picturesque Half Moon Bay, quickly reveals the sophisticated ride quality and the depth of comfortable appointments bound into a new fuel-thrifty light hybrid rendition of the 2012 LaCrosse, Buick’s mid-size luxury sedan.

LaCrosse, sleek in second-generation style drawn with taut lines and keen edgework, presents powertrain choices on 2012 issues with a new 2.4-liter four-cylinder engine rigged with ‘eAssist’ battery booster or a powerful 3.6-liter V6 with added flex-fuel E85 capability.

LaCrosse’s light hybrid version teams a thrifty but conventional 2.4-liter four-cylinder Ecotec engine that sips gasoline with a lithium-ion battery system and electric motor-generator to provide power assistance to the gas engine and improve the fuel economy numbers.

The aluminum-block four-cylinder engine, with dual overhead cams (DOHC), direct injection (DI) technology and variable valve timing (VVT), connects to a six-speed automatic transaxle, GM’s silky Hydra-Matic 6T40.

The lithium-ion battery system and electric motor-generator enables the Ecotec engine to shut off when the vehicle stops but automatically restart when the driver releases the brake pedal.

The Ecotec engine also ceases to run temporarily when the vehicle decelerates yet it kicks in again when the driver steps on the go-pedal.

The 115-volt battery contributes approximately 11 kW (15 hp) of electric power assistance and 15 kW of regenerative braking power.

Combined output for the Ecotec engine with eAssist equipment amounts to 182 hp at 6700 rpm with torque of 172 lb-ft at 4900 rpm.

The estimated fuel economy scores tally to 25 mpg City and 36 mpg Highway.

A DOHC 3.6-liter V6 with DI and flex-fuel capacity applies to LaCrosse’s top trim issues. The V6 develops 303 hp at 6800 rpm with torque rising to 264 lb-ft at 5300 rpm.

Transaxle is GM’s fuel-saving Hydra-Matic 6T70 six-speed automatic with tap-up/tap-down driver shift control.

With the V6 aboard, LaCrosse earns EPA fuel scores of 17 mpg City and 27 mpg Highway.

The front-wheel-drive architecture works for all LaCrosse editions, although there’s on-demand electronically controlled all-wheel-drive equipment available with the V6.

A redesigned second-generation LaCrosse was unveiled at the 2009 North American International Auto Show in Detroit bearing fresh exterior styling lifted from the Buick Invicta show car. It reached the streets as a 2010 model, built upon a front-wheel-drive platform which was designed in Europe and also used for Opel’s Insignia in Europe.

The design for LaCrosse’s luxurious five-seat passenger compartment occurred in China at GM’s Pan Asia Technical Automotive Center (PATAC). Sheetmetal styling originated in the United States at GM’s Technical Center in Warren, Mich., and the vehicle comes together at GM’s Fairfax Assembly Plant in Kansas City, Kan.

LaCrosse’s platform features a wheelbase which extends to 111.7 inches and the wheel track is wide at 61.7 inches front and 62.0 inches rear.

A fully independent suspension employs
MacPherson struts up front and twin-tube dampers with gas-charged valving and a hollow direct-acting stabilizer bar.

In the rear,
base editions use an H-arm arrangement for tight wheel control, while LaCrosse Touring Package adds 19-inch wheels with real-time active dampening and sport mode selectivity.

Brakes include a large disc at every wheel linked to an anti-lock brake system (ABS) with electronic brake force distribution (EBD) and a brake assist system (BAS), plus electronic vehicle skid controls (VSC).

LaCrosse’s exterior design looks sharp in a windswept package decorated with a chrome-plated prow flashing piercing optics from round projector-type headlamps on corners plus signature portholes cut into the front hood’s dual canted character lines.

LaCrosse’s tasteful two-tone passenger compartment provides seats for five including form-fitting front buckets and lots of amenities.

LaCrosse Base edition provides 17-inch alloy wheels, twin-zone automatic climate controls, power controls for windows and locks and mirrors, cloth upholstery, power driver seat, split-folding rear seatbacks, tilting-telescoping steering wheel, cruise control, Bluetooth connectivity and a 7-speaker audio kit with AM/FM/CD/USB.

Equipment packages add more gear:  Convenience, Leather, Premium I, Premium II, Premium III, Touring. The V6 is available on all save Base trim, yet it’s standard on Premium II, Premium III and Touring.

LaCrosse Touring rolls on 19-inch alloy wheels and employs an adaptive suspension, xenon headlamps with projector beam lenses, a blind spot warning system, rear vision camera, 40-gb hard drive and a navigation system, leather heated seats, heated steering wheel, head-up display, and a premium Harman/Kardon surround sound audio system with 11 speakers.

Buick posts MSRP figures for the 2012 LaCrosse in a range from $30,180 to $38,310.

2012 BUICK LaCROSSE SEDAN SPECIFICATIONS

• Description: Mid-size luxury sedan
• Model options: LaCrosse Base, LaCrosse Convenience, LaCrosse Leather, LaCrosse Premium I, LaCrosse Premium II, LaCrosse Premium III, LaCrosse Touring
• Wheelbase: 111.7 inches
• Overall length: 196.9 inches
• Engine size:
  • DOHC 2.4-L I4/VVT/eAssist + electric motor-generator
  • DOHC 3.6-L V6/VVT
• Transmissions/speeds:
  • 2.4:   Auto/6
  • 3.6: Auto/6
• Rear/front drive
  • 2.4-L: FWD
  • 3.6-L: FWD or AWD
• Steering: EPS/rack and pinion
• Braking Power: 4-disc, ABS/EBD/BAS/TCS/VSC/TPMS
• Air bags: 2 (front), 2 (side), 4 (side curtain)
• EPA mileage est. city/hwy.:
  • 2.4: 25/36 mpg
  • 3.6: 17/27 mpg
• MSRP range, est.: $30,180 to $38,310