Mercedes-Benz gives its biggest SUV a minor facelift for 2010, updating the GL-Class's headlights, taillights, and exhaust pipes. The bumpers sport a freshened look as well, with rows of LED daytime running lights bracketing the front bumper. In addition, the GL-Class receives new alloy wheels, which dress up the exterior. The interior also receives an update. A new instrument cluster design includes raised markers on the speedometer and tachometer, which create a 3-D effect, and upgraded seats feature adjustable head restraints and redesigned seat upholstery. In addition, the automaker makes Burl Walnut trim a standard feature on the GL-Class and offers interior ambient lighting as a new option for 2010. The GL-Class consists of GL450 and GL550 trims for 2010. Both trims seat seven passengers in three rows, and both offer comfortable, well-equipped interiors with plenty of upscale features. The GL450 comes standard with such features as MB-Tex leatherette upholstery, heated eight-way power-adjustable front seats, a leather-wrapped multifunction steering wheel, aluminum interior trim, and an 8-speaker audio system with a 6-CD changer and MP3 input jack. Automatic climate control and cruise control also come standard. A front console with cubbies and eight cupholders throughout the cabin are among the interior storage spaces. The GL550 adds such features as leather seating, memory settings for the front seats, and a 610-watt, 11-speaker Harman Kardon surround-sound audio system with Sirius satellite radio. The GL550 also comes equipped with the COMAND system with voice-activated navigation and real-time traffic updates, although many owners feel the recently upgraded system remains too complicated to operate effectively. A Parktronic electronic front and rear parking aid also comes standard in the GL550. Both trims feature a front power tilt-open sunroof and a rear fixed panorama sunroof, both with sunshades, which enable passengers to control the amount of light entering the cabin. The power-operated, 50/50-split third-row seats fold flat in about 5 seconds at the touch of a button. With the second row also folded flat, the GL-Class offers 83 cubic feet of cargo space. The GL550 includes a power tailgate as standard equipment. For power, the GL450 comes equipped with a 4.6-liter, DOHC V8 engine generating 335 hp and 339 lb-ft of torque, while the GL550 retains its 5.5-liter, DOHC V8, which pumps out 382 hp and 391 lb-ft of torque. Both engines link to a seven-speed automatic transmission with two overdrive gears, which help to conserve fuel at cruising speeds. In addition, the 4MATIC AWD system comes standard in both GL-Class trims. Mercedes equips the GL-Class with a full range of airbags, including side head curtain airbags. Other safety features include antilock brakes, four-wheel traction control, and electronic stability control. Heated exterior mirrors, front foglights, HID headlights with washers, and Rainsense wipers are among the exterior features for the GL-Class. The GL450 rides on 19-inch alloy wheels, while the GL550 cruises on beefy AMG-designed 21-inch alloy wheels.