The steering in the all-new 2013 Mercedes-Benz GL three-row, seven-seat SUV feels light to the touch and loose on-center. This shortcoming is not attributable to any flaw in the electrically assisted rack-and-pinion gear or lapse on the part of the engineers who fret over chassis tuning. Instead, blame 50 clinic participants鈥擲outhern Californians owning a current Mercedes ute or a competitive SUV鈥攚ho drove GL prototypes and said that light and loose is how steering should be. Shortly after it was introduced six years ago, the GL mounted the throne in the luxury-SUV castle with a C/D comparison-test win. It not only impressed us with room and comfort but also scored high in the steering, handling, ride, and fun-to-drive categories. In two-plus-ton trucks, such virtues are as rare as bud vases. Mercedes resisted fiddling with the basic formula that made the original GL the most popular large luxury SUV, even at the end of its six-year life span. Changes to the outside dimensions, chassis layout, and exterior design are modest. Thanks to more extensive use of aluminum (hood, front fenders, suspension components), magnesium (dash support structure), and reinforced plastic (engine mounts), curb-weight bloat has been kept to a minimal 50 pounds.

The steering in the all-new 2013 Mercedes-Benz GL three-row, seven-seat SUV feels light to the touch and loose on-center. This shortcoming is not attributable to any flaw in the electrically assisted rack-and-pinion gear or lapse on the part of the engineers who fret over chassis tuning. Instead, blame 50 clinic participants鈥擲outhern Californians owning a current Mercedes ute or a competitive SUV鈥攚ho drove GL prototypes and said that light and loose is how steering should be. Shortly after it was introduced six years ago, the GL mounted the throne in the luxury-SUV castle with a C/D comparison-test win. It not only impressed us with room and comfort but also scored high in the steering, handling, ride, and fun-to-drive categories. In two-plus-ton trucks, such virtues are as rare as bud vases. Mercedes resisted fiddling with the basic formula that made the original GL the most popular large luxury SUV, even at the end of its six-year life span. Changes to the outside dimensions, chassis layout, and exterior design are modest. Thanks to more extensive use of aluminum (hood, front fenders, suspension components), magnesium (dash support structure), and reinforced plastic (engine mounts), curb-weight bloat has been kept to a minimal 50 pounds.

All-wheel drive, an air-spring suspension, French-stitched leather, and wood trim are standard. To keep demanding customers in the fold and to thwart competitors, Mercedes heaped in its best technology. Three new engines鈥攁 3.0-liter turbo-diesel V-6 and a pair of twin-turbo 4.7-liter gas V-8s鈥攂ring more power and torque, quicker acceleration, and mileage improved by 1 to 3 mpg. The enhanced seven-speed automatic now has paddle shifters; these instruments are curious enough, in this application, to suggest an attempt by Mercedes engineers to keep in some of what the focus group took out. As an antidote to ever-thicker roof pillars, there鈥檚 an optional camera system providing a bird鈥檚-eye view of the immediate surroundings. A new On/Off-Road package includes a low-range transfer case, a center-diff lock, and ride-height adjustment. Optional adaptive dampers and anti-roll bars check body motion. New available safety aids forestall rear-end collisions, lane changes caused by crosswinds, and nodding off at the wheel.

For those who napped during driver鈥檚 ed, automatic parking can be had. New electrical architecture powers a 4.5-inch instrument-cluster display, a seven-inch center screen, and a smarter COMAND infotainment system. An ingenious second-row seat is the GL鈥檚 must-have option. The major improvements over the previous generation are third-row access from both sides and power operation. To provide easy entry, the rear doors are long without feeling ungainly. Touch a button, and the second-row backrest folds and a portion of the 60/40-split bench flips forward to clear a path to the peanut gallery. When the mission is hauling freight instead of a soccer team, the center row鈥檚 bottom cushions flip鈥攆ollowed by the middle and rear backrests鈥攜ielding a nearly level load floor and 94 cubic feet of cargo space. Because of limited third-row kneeroom and a second-row center-seat position equipped with a fold-down armrest/cup holder, the GL is no seven-passenger limo, but it can nicely accommodate four adults, three kids, and 16 cubic feet of luggage. The three GL engines hum the same basic tune, raising their voices only in response to jabs of the accelerator. All suffer from turbo lag.

63,305 GL350 welcomes newbies to the diesel fan club with smart off-the-mark acceleration and 500-mile runs between fuel stops. 64,805 GL450; what its direct-injection V-8 loses in torque versus the GL350鈥檚 diesel V-6, it more than makes up in power, rev range, and passing acceleration (all three models are rated to tow 7500 pounds). 87,805, is the performance and equipment king; adjustable dampers and 21-inch wheels and tires are standard here. Tuning the steering according to clinic results was a bad idea, but once a GL exceeds around-town velocities, effort at the wheel builds and on-center slack becomes less of an issue. During New Mexico test drives, we found cruising comportment to be inversely proportional to tire-and-wheel diameter. The 19-inchers standard on the GL350 and GL450 require the least amount of minding to maintain a straight path. Stepping up through the optional 20s and 21s, we noticed increasing amounts of ride jiggle and road wander. Switching the adaptive dampers from comfort to sport also diminished the GL鈥檚 ability to lock on to a straight path. We whined persistently about the previous GL鈥檚 squishy brakes. Pedal travel remains longer than it should be, but once the slack is taken up, there鈥檚 a firm feeling underfoot this time around. Mercedes-Benz鈥檚 grand luxe trump card arrives early next year: a GL63 AMG energized by a 550-hp, 5.5-liter twin-turbo V-8. Pray the clinic crowd never gets its paws on that one.

Photo 4/14 | Updated front-end styling includes changes made to give the GLS a familial resemblance to other modern Mercedes-Benz vehicles. The rounded front grille, reshaped headlamps, and restyled LED light pipes look similar to those on the current C-Class, E-Class, and S-Class sedans. Key exterior alterations include an updated front fascia with a new grille and headlamps that bring the GLS in line with its S-Class sibling. Around back, restyled LED taillights keep those behind you abreast of the goings-on, while new wheel designs update the rolling stock. Even with its updated appearance, bold the GLS is not, favoring handsome lines that should age better than the wild styling cues of its more trendy competition. Photo 6/14 | A new three-spoke steering wheel and instrument cluster display bring subtle changes to what was already a very user-friendly, luxurious place to spend time. Photo 7/14 | Each of the GLS350d鈥檚 seven passengers are all but guaranteed plenty of space.