General Motors today reveals redesigned-for-’14 models of the Buick LaCrosse and Regal 5-passenger sedans, featuring spruced-up exterior and interior styling, as well the addition of new safety, convenience and infotainment technologies.

The LaCrosse and Regal represent two core products for the brand, which has been mounting a comeback in recent years by shaking off a stodgy reputation for a warmer, more inviting and youthful personality.

So far, the strategy has been working. New products have combined with the fresh marketing approach to push Buick’s conquest rate, or the percentage of non-GM customers buying its products, to more than 43% in 2012 from 28% in 2007.

But last year the brand hit a sales plateau. Deliveries rose 1.6% to 180,408 in 2012 from 177,633 in 2011 against an industry that gained 13.4%, according to WardsAuto data. LaCrosse sales fell 2.4% to 57,076 units and Regal volume plummeted 38.6% to 24,652.

Refreshed versions of the LaCrosse and Regal, which bowed in their current forms in 2010 and 2011, respectively, could put Buick sales back on track.

The brand’s popular Enclave large cross/utility vehicle received a refresh late last year, while the Verano small sedan celebrated its first birthday late in 2012 and the all-new Encore small CUV recently arrived at U.S. dealers.

“We evolved the interior and exterior design, increased luxury amenities and materials and enhanced the safety and personal technologies to give customers more reasons than ever to rediscover Buick,” Tony DiSalle, U.S. vice president-marketing, says of the new models.

Exterior upgrades to the ’14 LaCrosse include new wing-shaped, light-emitting-diode daytime running lamps and updated headlamps moved farther outboard and containing brand-specific LED accents. A new front fascia and hood design feature a more prominent grille, and active lower-grille shutters now appear on every model to improve aerodynamics.

The Fairfax, KS-built LaCrosse adds a fresh rear fascia with newly designed LED taillamps, fully enclosed exhaust ports framed in chrome and a rear spoiler now integrated into the decklid.

Other exterior updates include new 18-, 19- and 20- in. wheel and tires packages, as well as revisions to certain chassis and suspension items to improve ride and handling.

Inside, the LaCrosse receives a new human-machine interface to support the brand’s latest IntelliLink infotainment system and its 8-in. (20-cm) color touchscreen. The center stack now integrates into the floor for added storage space.

GM redesigns the front seats and adds 4-way adjustable headrests. New door panels receive updated switchgear for the locks, seat memory and trunk release.

A new interior package called “Ultra Luxury” adds a synthetic suede headliner and door-pillar covers, semi-aniline leather seating and authentic Tamo Ash wood trim, the auto maker says in product information released ahead of the reveal.

The ’14 LaCrosse also receives GM’s latest suite of active safety technologies, such as forward-collision alert, lane-departure warning, rear-cross-traffic alert and full-speed-range adaptive cruise control, parceled into two option packages.

Powertrain choices remain a standard 182-hp 2.4L 4-cyl. engine mated with GM’s eAssist mild-hybrid system and an optional 304-hp 3.6L V-6 with gasoline direct-injection technology. Both deliver power through 6-speed automatic transmissions.

The ’14 Regal benefits from updated exterior styling, featuring the addition of LED technology to the DRLs and taillamps, and a revised grille. Additional subtle design cues enhance its sporty proportions and convey a more upscale and contemporary look.

Inside, the Regal gets an updated instrument panel capped by a larger, 8-in. touchscreen. High-performance GS models gain a new level of IP customization.

“The advanced technologies in the 2014 Regal complement its flowing passenger environment, with integrated elegance,” says Ven Lai, creative designer-color and trim. “The cabin’s rich, tailored elements are executed in warm tones and soft-touch materials that enhance the premium ambience in a thoroughly contemporary manner.”

A fashionable, 2-tone Cocoa-Saddle leather combination joins three other interior color schemes for ’14.

The Oshawa, ON, Canada-built Regal will offer the same suite of GM safety technologies as optional equipment in two packages and an updated IntelliLink infotainment system.

The ’14 Regal Turbo’s 2.0L turbocharged 4-cyl. engine with GDI has been boosted to 259 hp from a previous 220 hp.

The Regal GS, which since its launch has used a version of the current 2.0L tuned for 270 hp and 295 lb.-ft. (400 Nm) of torque, will add the new 2.0L in ’14 without a boost in output over the standard turbo model.

The GS will retain its unique styling and racier chassis and suspension tuning.

GM also enhances the torque curve on the engine, one of a family of 4-bangers to win a 2013 Ward’s Best Engines award, to release 90% of its peak 260 lb.-ft. (353 Nm) of torque between 1,700 and 5,500 rpm for more exhilarating performance.

The standard powertrain remains the 2.4L 4-cyl. engine with eAssist mated to a 6-speed automatic transmission.

The Regal will add an all-wheel-drive option for the first time, a technology the GS show car carried in 2010.

The Haldex system includes wheel-slip management and an electronic limited-slip rear differential. The system allows the Regal to tailor torque split between the front and rear wheels, with the ability to send up to 90% to the rear if needed.

The AWD system mates to GM’s HiPer Strut front-suspension technology, which in front-drive models reduces torque steer and mitigates unwanted roadway feedback in the steering system.

jamend@wardsauto.com