Buick LaCrosse Mid-size Sedan Offers a Thrifty Ecotec Engine
Bob Plunkett, Fri, 18 Mar 2011 03:53:42 PDT
MILAN, Mich. -- We're scooting down a narrow section of road scored through Michigan farmlands just beyond suburban fringes of Detroit to test the get-up-and-go power of a new fuel-thrifty engine installed in two front-wheel-drive (FWD) trim versions of the 2011 LaCrosse, Buick's mid-size luxury sedan drawn with taut lines and keen edgework.
LaCrosse CX and CXL stock GM's Ecotec 2.4-liter aluminum-block four-cylinder engine outfitted with dual overhead cams (DOHC), direct injection (DI) technology and variable valve timing (VVT), and it connects to a six-speed automatic transaxle, the silky and smart Hydra-Matic 6T45.
The Ecotec four plant in LaCrosse generates 182 hp at 6700 rpm and 172 lb-ft of torque at 4900 rpm.
And the federal EPA sets fuel economy numbers for this LaCrosse powertrain at 19 mpg City and 30 mpg Highway.
One driver steering the 2011 LaCrosse CXL straps securely in a leather-lined bucket and faces the arching instrument panel fitted with white-faced analog gauges rimmed in beads of chrome.
Peering directly through the windshield above the instrument panel, we see a display in neon-green numbers of the vehicle's speed and critical engine data projected magically on glass in the driver's line of sight.
Gripping a padded steering wheel, we turn it to match the right-angle turns at mile-length sections and the crisp rack and pinion steering mechanism -- aided by a variable-ratio electric power boost -- complies. With the engine's muscle directed to the front wheels, LaCrosse turns in deft zig and zag maneuvers which reveals its agility on pavement.
Step on the accelerator after rounding one of these corners and the Ecotec engine reacts quickly to build momentum again.
The four-cylinder engine on 2011 LaCrosse CX and CXL FWD models supplants a 3.0-liter V6 used on 2010 models.
A DOHC 3.6-liter V6 with DI and VVT is available for all 2011 models -- it's standard on LaCrosse CXL AWD (all-wheel-drive) and top-trim CXS but optional for the base CX and LaCrosse CXL FWD.
The V6 develops 280 hp at 6300 rpm with torque rising to 259 lb-ft at 4800 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 LaCrosse nameplate stems from a Buick design concept exhibited in year 2000 on the auto show circuit, while a smoothly sculpted four-door sedan wearing the LaCrosse badge showed at the 2004 Chicago Auto Show.
The initial production version of LaCrosse rolled out in 2005 as replacement for several aged Buick sedans.
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, which appeared at the 2008 Beijing Auto Show.
It reached the streets as a 2010 model trimmed as CX, CXL FWD, CXL AWD and the CXS.
Its platform was designed in Europe and underpins other products such as 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 for 1.2 inches longer than the wheelbase of the previous platform, and the wheel track is wide for keen chassis dynamics to set up superior handling traits.
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, a base CX edition and the CXS with 18-inch wheels use a four-link design with twin-tube gas shocks plus a direct-acting stabilizer bar.
LaCrosse CXL and CXS with Touring Package differ in the rear suspension by adding an H-arm arrangement for tighter wheel control, 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 GM's StabiliTrak electronic vehicle skid control system.
LaCrosse CX rolls on 17-inch steel wheels or optional 17-inch aluminum alloys, with CXL and CXS stocking 18-inch aluminum rollers and the CXS offering optional chrome plated 19-incher.
The FWD architecture works for all LaCrosse editions, although for CLX there's that on-demand electronically controlled AWD equipment available.
This intelligent system uses a computer and wheel sensors in conjunction with the ABS and StabiliTrak to determine how much power to apply at each wheel for maintaining tire traction on slippery or wet pavement.
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.
The roofline remains low, dipping down in front in line with the windshield but mounting a smooth arch over the cabin before tapering to a rolled tail off the trunk deck.
LaCrosse's tasteful two-tone passenger compartment provides seats for five including form-fitting front buckets and lots of amenities.
LaCrosse CX stocks premium cloth upholstery, power controls for windows and door locks and mirrors, a steering wheel that tilts and telescopes, air conditioning, heated outside mirrors and an audio kit with AM/FM/CD/MP3.
LaCrosse CXL adds leather-clad seats, twin-zone automatic climate controls and foglamps, while CXS gets perforated leather with front seats heated and cooled.
Optional gear includes high intensity discharge (HID) headlights with adaptive forward lighting, GM's Side Blind Zone Alert, Bluetooth phone connectivity, navigation with rearview camera, a vast sunroof and a backseat DVD kit.