Infiniti will show off refreshed versions of its largest models today at the New York International Auto Show, revealing the ’15 Q70 (M) sedan and QX80 SUV.

The current-generation M and QX80, called the QX56 at its launch, went on sale in the U.S. in March 2010 and July 2010, respectively.

Both models receive freshened exterior styling and a variety of driver-assist technologies, while the Q70 adds a new long-wheelbase model.

“We know our customers desire more choice and prestige (and) the long wheelbase Q70 is our offer to them,” Vincent Gillet, vice president-marketing for Infiniti, says in a statement.

Infiniti calls the Q70’s design more dramatic and upscale than before. Changed elements include the car’s grille, now boasting a more 3-D look; a wave-like bodyline that flows from the grille to the new LED combination lights in the rear; a flatter trunk lid; and slimmer rear bumper.

The Q70 Sport model gets a unique front bumper for a lower, wider appearance and a rear bumper finished in glossy black paint near the bottom.

The Q70 continues to offer wood and leather trim inside, as well as such creature comforts as a 7-in. (18-cm) display screen and 10-way heated driver and front-passenger seats.

The LWB model’s rear legroom climbs 5.9 ins. (15 cm) over that of the standard Q70. Heated rear seats, rear reading lights and a 12V outlet also can be had in this variant of the car.

Efforts to reduce cabin noise are made for ’15, with more insulation and sealing added and wheels stiffened.

The Q70 retains the M’s array of powertrains: a 3.7L V-6 engine, a 5.6L V-8 engine and a hybrid propulsion system.

Peak output for the 3.7L and 5.6L goes unchanged at 330 hp/270 lb.-ft. (366 Nm) of torque and 420 hp/417 lb.-ft. (565 Nm) respectively. The new LWB model uses the 5.6L and sees a slight reduction in output, to 416 hp/414 lb.-ft. (561 Nm).

The hybrid system, a 2012 Ward’s 10 Best Engines winner, combines a 3.5L V-6 engine, 50-kW (67-hp) electric motor and a lithium-ion battery pack, for a still-hefty 360 hp.

Tweaked shock absorbers minimize vibrations on uneven roads, as well as reduce “shaking and bobbing.”

The Q70 improves upon the M’s safety features by adding predictive forward-collision warning, around-view monitor, backup-collision intervention and forward emergency braking.

QX80 Borrows Design Cues From Q50

Infiniti also massages its largest model, the QX80 fullsize SUV, for ’15, updating the front fascia to resemble that on the Q50 sport sedan.

A slew of LEDs are added as well for turn signals, fog lights and high/low-beam headlights.

QX80s with the deluxe technology package get chrome-plated outside rear-mirror caps.

In all versions of the SUV, a rear-bumper protector is added as standard to reduce damage when loading and unloading cargo.

Three new exterior colors, a blue, gray and white, are offered for ’15.

In the large luxury SUV segment the wheels keep getting bigger and Infiniti claims to one-up the competition with a new 22-in., 14-spoke, forged aluminum-alloy design. However, the all-new ’15 Cadillac Escalade also offers 22-in. wheels, although topping out at seven spokes.

Standard QX80 wheels are newly designed 20-in. machine-finished aluminum alloys.

Interior updates to the Infiniti SUV include color-and-wood atmospheres with more contrast. Tuscan Burl wood trim is replaced by a darker Mocha Burl with a more reddish grain, while the Mocha Burl of the current generation’s deluxe touring package is changed to a Stratford Burl with a heavier, “fine-furniture-like” appearance, Infiniti says.

Wheat- or graphite-color leather seating still is available, but the latter now gets silver-contrast stitching instead of black stitching.

Technologies added for ’15 include the Q50’s advanced high-beam assist, standard on all grades and automatically dropping the high beams to low beams when a car approaches, as well as predictive forward-collision warning.

Most technical specifications of the QX80 carry over from ’14 to ’15, including its 400-hp 5.6L V-8 and 8,500-lb. (3,856-kg) maximum towing capacity.

Infiniti sold 5,283 copies of the M in the U.S. last year, down 42.1% from 2012, WardsAuto data shows, while combined sales of the ’14 QX80 and ’13 QX56 tallied 13,148 units, down 14.1% from the QX56’s 15,310 in 2012.

Mercedes-Benz had the top-selling mid-large luxury sedan in the U.S. last year with the E-Class, delivering 69,803 units.

Infiniti was the segment leader in large luxury SUVs, topping Cadillac Escalade sales in 2013 (12,592), if QX56 and QX80 deliveries are combined.

cschweinsberg@wardsauto.com