This week, U.S. journalists are test-driving the very first new-generation 2013 GL-Class sport utility vehicles arriving in the U.S. The second-generation of the award-winning Mercedes-Benz GL-Class sport utility is making its debut for the 2013 model year. The launch of the new full-size GL marks the introduction of a significant new safety system, COLLISION PREVENTION ASSIST, which uses a dedicated radar sensor to monitor the distance to a vehicle in front and to stationary objects. If the system senses a risk of imminent collision, it pre-charges the brakes and alerts the driver with a warning beep and flashing light on the dash.
Many New Safety Systems
The new GL-Class is loaded with other new safety systems such as ATTENTION ASSIST, ADAPTIVE BRAKE technology, mbrace2 telematics and Crosswind Stabilization. Slightly longer, wider and taller than the first-generation SUV, new convenience features include a COMAND control knob, a color instrument cluster display, power liftgate, and a 115-volt outlet under the second-row seats.
Among the new GL options are an ACTIVE CURVE SYSTEM, On/Off-Road Package, Active Parking Assist, Active Lane Keeping Assist, a 360-degree Surround View camera, Panorama Roof and power EASY-ENTRY for third-row passengers.
The 2013 GL Lineup
The new GL model lineup for 2013 ranges from the fuel-sipping GL350 BlueTEC (240 hp, 455 lb.-ft.) with a V6 turbodiesel to the high-performance GL63 AMG (550 hp, 560 lb.-ft.) that’s powered by a hand-built AMG 5.5-liter biturbo, direct injection V8. Between these two contrasting models are the popular GL450 (362 hp, 406 lb.-ft.) and GL550 (429 hp, 516 lb.-ft.), both equipped with new direct-injection biturbo V8 engines.
Electromechanical Rack-And-Pinion Steering
The 2013 GL-Class comes with new electrically-assisted rack-and-pinion steering. Not only does the new electric steering provide built-in speed-dependent power assist, but it also offers fuel savings. The engine no longer has to turn a hydraulic power steering pump, and the new steering only uses electrical power when the wheel is being turned. Mounted ahead of the front wheel center, the steering gear unit has a variable mechanical ratio that operates more directly, or slightly faster, in the center position, which enhances agility and handling.
Active Parking Assist
The new electric steering assist also makes other innovative systems possible, such as optional Active Parking Assist, which makes parallel parking a stress-free cinch. Below about 20 mph, a “P” icon appears in the dash to show that an electronic search for a parking space is active, and whenever an adequate-size parking space is found, an arrow appears next to the “P” icon. When reverse is engaged and the driver confirms Active Parking Assist is desired, the system initiates automatic steering as the driver controls acceleration and braking at speeds below seven mph. The system allows two forward corrections, after which the wheels are straightened. Active Parking Assist also includes an automatic exit feature.
ACTIVE CURVE SYSTEM
Not to be confused with Active Curve Illumination, the optional ACTIVE CURVE SYSTEM is a semi-active suspension that uses electronic sensors, an engine-driven hydraulic pump and electronically controlled hydraulic valves to reduce body lean. Instead of conventional torsional stabilizer bars at the front and rear, the stabilizer bars in the ACTIVE CURVE SYSTEM are essentially split in the center and connected to rotary hydraulic actuators.
Whenever the vehicle is in a curve, the actuators counteract lateral pitching, reducing the natural tendency of the body to roll and lean in curves. Lower side forces means increased stability and driving pleasure, especially at high speeds, as well as less shifting of occupants.
An optional On/Off-Road package features a two-speed electronically controlled transfer case that gives the GL-Class true off-road capability. High range provides 1:1 on-road gearing, and selecting low range engages a 2.93:1 ratio for impressive off-road control and climbing ability.
The On/Off-Road package includes an Off-Road switch on the center console that activates special computer algorithms to enhance engine, transmission, ABS, ESP, traction control performance in off-road conditions. In addition, a six-position rotary dial allows the system to be customized, including selecting low range, engaging a center differential lock and increasing ground clearance in increments of 1.2, 2.4, and 3.5 inches.
4MATIC Four-Wheel Drive Sets a Trend
All four GL models come with proven Mercedes-Benz 4MATIC all-wheel drive. As modern all-wheel-drive systems become more refined, they are becoming more popular, especially in the luxury car market. With negligible weight and fuel-efficiency tradeoffs, full-time four-wheel drive provides year-round traction and stability benefits on both wet and dry roads.
ATTENTION ASSIST Cautions “Time For A Rest? “
Among the many new life-saving features on the GL-Class is the innovative ATTENTION ASSIST system that can alert the driver to the first signs of drowsiness, a factor that causes more than 100,000 accidents a year in the U.S. A steering sensor is coupled to smart software that uses 70 parameters to establish a unique driver profile during the first 20 minutes of driving. Between 50 and 112 mph, the system identifies the erratic steering corrections drivers make as they begin to get drowsy and triggers an audible warning, and a “Time for a Rest?” message with a coffee cup icon appears in the instrument cluster.
More Safety Systems Assist the Driver
Other examples of trailblazing safety innovations include: Active Lane Keeping Assist, which alerts the driver by simulating rumble strip vibration in the steering wheel if the car drifts from its lane without the turn signals on. It operates at speeds above 37 mph via a system that recognizes lane markings, thanks to a small camera in the windshield and a computer that analyzes the video images. Active Lane Keeping Assist incorporates an intervention feature, in which ESP braking automatically helps correct the car’s course if the driver doesn’t heed the initial warning.
Active Blind Spot Assist monitors both blind spots behind and to the side of the vehicle. Whenever a turn signal is activated with a vehicle in the blind spot, the driver gets visual and audible warnings. Active Blind Spot Assist also incorporates the ESP intervention feature, which automatically helps correct the car’s course if the driver doesn’t heed the initial warning.
Mercedes-Benz Safety is Standard
The new COLLISION PREVENTION ASSIST system monitors the distance to vehicles in front and to stationary objects with a dedicated radar sensor. If the system senses a risk of imminent collision, it alerts the driver with a warning beep and flashing light on the dash. COLLISION PREVENTION ASSIST also networks with standard Brake Assist to prepare for emergency braking, so that maximum power assist is available as soon as the driver applies the brakes.
In addition to standard COLLISION PREVENTION ASSIST, The GL-Class line comes with ESP® stability control, ABS anti-lock brakes, two-stage adaptive air bags for the driver and front passenger, driver’s knee air bag, seat-mounted side air bags in front and rear, curtain
side air bags and adaptive belt tensioners and belt force limiters.
PRE-SAFE® Gives The GL-Class Reflexes to Protect Occupants
Standard on the new GL, PRE-SAFE® is a revolutionary safety system that can actually sense an impending collision before it happens and take measures to protect occupants during those valuable seconds before impact. The PRE-SAFE system automatically tightens the front seat belts before a possible impact, and, on some models, the front passenger seat moves to a position that can provide better protection. Side windows close to provide better support for the curtain air bags, and if the system senses an impending rollover, the sunroof also closes.
Rich, Sporty Interiors with Flexible Cargo Space
The exterior appearance of the new GL line includes sleek bumpers and front grille, chrome window trim and front and rear skid plates. LED technology is used for taillights and daytime running lights.
Inside, the luxury SUVs are fitted with heated power front seats, genuine wood trim and a retractable glass sunroof. New options include a double-sized power Panorama sunroof with a fixed glass panel over the third-row seats and multi-color ambient lighting.
The two third-row seats can be stowed electrically at the push of a button, either separately or together, to provide a totally flat cargo floor. For easy access to the 3rd-row seats from both sides, a manual EASY-ENTRY feature is standard. Optionally available is power EASYENTRY folding of the second-row seats.
All GL-Class models feature four-wheel independent suspension and height-adjustable AIRMATIC suspension for unprecedented comfort and handling. The GL550 can be easily identified by a unique exterior styling treatment that includes fender flares, more aggressive front and rear aprons, chrome trim and 21-inch AMG wheels.
In Command with COMAND
A standard COMAND system features a high-resolution seven-inch color display screen with a COMAND controller, AM / FM / HD radio, in-dash, six-disc DVD / CD changer and a Bluetooth interface that allows a phone still in a pocket or purse to be operated through the car’s audio system. It can be equipped with an optional iPod/MP3 interface, SIRIUS satellite radio and enhanced voice control. The COMAND screen can play tracks stored on a data CD, DVD or SD memory card.
The system can also display maps and directions for the optional hard-drive navigation system, which can be set up for SIRIUS real-time traffic info and Zagat restaurant ratings as well. All GL-Class models can be equipped with an optional 830-watt 14-speaker digital harman / kardon Logic7 audio system and a rear-seat entertainment system that includes two eight-inch screens, wireless headphones and an integrated DVD player that enables dual-source capability.
GL350 BlueTEC Boasts Impressive Fuel Economy
Available in all 50 states, thanks to an innovative AdBlue exhaust treatment system that helps the diesel meet the most stringent emissions limits, the diesel-powered GL350 BlueTEC delivers impressive performance, low exhaust emissions and great fuel economy. With 240 hp and a whopping 455 lb-ft. of torque, the GL350 BlueTEC features an innovative 3.0-liter V6 diesel engine with the torque of a V8 and the fuel economy to rival some four-cylinders. Equipped with the latest CDI (Common Rail Direct Injection) technology, this electronically injected and turbocharged diesel engine is changing consumers’ dated perceptions about diesels.
BlueTEC — A Modular Technology
BlueTEC diesel technology is helping to expand the company’s already broad product portfolio in the U.S. market. In addition, the pioneering role of Mercedes-Benz in modern diesel engines is playing a key role in the company’s future products that could also include hybrids, advanced piston engines and fuel cells.
The seven-seat SUV also boasts impressive cruising range – more than 600 miles at highway speeds. For greater utility, V8-like pulling power makes the GL350 BlueTEC ideal for towing when it’s equipped with an optional 7,500-lb. Class IV trailer hitch.
BlueTEC incorporates an oxidation catalyst and a maintenance-free particulate filter as well as new techniques for reducing nitrogen oxide emissions – the last type of exhaust gas that’s higher in diesel vehicles than gasoline engines. The BlueTEC diesels feature a NOx storage converter in combination with an SCR catalytic converter and AdBlue injection to lower NOx emissions. The AdBlue system injects just the right amount of an aqueous carbamide solution into the exhaust flow, which releases ammonia (NH3), reducing nitrogen oxides to harmless nitrogen and water in the downstream SCR converter.
Biturbo V8 Engines
With a choice of three direct-injection, biturbo V8 engines, the new GL attains better gas mileage while producing more power -- an astounding feat, considering that increasing either power or fuel economy usually decreases the other. The biturbo V8 engines feature direct fuel injection, twin turbochargers and multi-spark ignition.
Piston crowns are four millimeters thicker to handle the high combustion pressures of a turbocharged engine, while shorter connecting rods allow existing block dimensions to be retained. Like its predecessor, the new engines have aluminum cylinder heads, pistons and cylinder block (with cast-in Silitec cylinders), as well as a crankshaft, connecting roads and valves made of special forged steel.
Direct Fuel Injection
While most gasoline engines have used indirect port fuel injection in the past, the GL engines make use of industry-leading electronics technology first used on Mercedes-Benz diesels – electronic fuel injectors that spray gasoline directly into the combustion chambers. Featuring a piezo-ceramic crystalline element that changes shape when electrical current is applied, blazingly fast piezo injectors make it possible to design very sensitive and precise injection systems, including the ability to program several small injections with each piston stroke.
The first injection is sprayed into the combustion chamber as the piston is descending on the intake stroke. Depending on speed, load and temperature conditions, another injection or two takes place during the compression up-stroke before ignition, forming a stratified mixture. A fourth injection can stabilize combustion if it’s needed.
Multi-Spark Works with Multi-Squirt
Working together with the spray-guided direct injection, a rapid multi-spark ignition system begins combustion with the first spark, but has the capability to recharge and deliver up to three more sparks within a single millisecond, creating a gas plasma with more expansion than conventional ignition.
The time lapse between sparks is adjustable, so combustion duration can actually be controlled, resulting in two percent better fuel economy, and a total of four percent improvement in combination with its companion direct fuel injection system.
Refined Variable Valve Timing
Mounted on the ends of the intake and exhaust camshafts, the hydraulic camshaft adjusters that vary valve timing are 35 percent faster than in the past, and with a wider range of 40 crankshaft degrees. Despite their improved performance, they’re also more than a half inch smaller in height and width.
More Efficient Cam Chain Drive
Smaller valve timing adjusters are made possible by a revised cam chain drive, in which the crankshaft drives an intermediate shaft above the crank. In turn, the intermediate shaft drives two short chains – one for each cylinder bank – that loop around the intake and exhaust camshaft drive sprockets. The latest chain drive results in less tension and lower chain dynamics, for even lower friction and less noise.
A fourth chain drives a variable vane-type oil pump in the bottom of the engine. At low engine speed and load, the oil pump only generates about 28 psi (or two bar) of oil pressure, and nozzles that spray cooling oil on the pistons are inactive. As engine speed and load increases, oil pressure rises, and the oil spray nozzles are turned on. In this way, less energy is used when less cooling and lubrication is needed.
Three-Phase, Low-Load Cooling System
Even the cooling system is significantly refined, beginning with a two-stage flow circuit through the cylinder head. This coolant flow results in better heat dissipation, despite lower coolant pressure, so that the water pump uses less engine power.
A three-phase cooling system helps the engine warm up very quickly. When the engine is first started, no coolant circulates. Then, as the engine warms up, coolant begins to circulate within the engine, but not through the radiator. Only when the coolant temperature reaches 221 degrees Farenheit (or 189 degrees F. under high load), coolant also circulates through the radiator. Coolant circulation through the heating system for the car’s interior is controlled separately.
The Building Blocks
Assembling the biturbo V8 engine underscores its efficient design. An exceptionally stiff forged-steel crankshaft is bolted into a pressure-cast aluminum block, and an aluminum oil pan also contributes to block rigidity.
Aluminum pistons are mounted on the connecting rods, then slid into the silicon-aluminum sleeves, which are an integral cast-in part of the block. Connecting rods must be made in two pieces for assembly on the crankshaft, and Mercedes engines use hollow, forged steel rods that initially are made in one piece, then hydraulically “cracked,” instead of being machine-cut and reground. The irregular fracture provides a very strong, durable fit, even at high engine speeds, and shortens the production process since re-grinding isn’t necessary.
The two cylinder heads are bolted onto the block, and twin camshafts are installed in each head, with cam drive chains looping around the intake and exhaust cam sprockets. Double-wall piping keeps the exhaust air as hot as possible leading to a catalytic converter below each cylinder bank.
The 2013 GL-Class line is equipped with an enhanced seven-speed automatic transmission that provides even better fuel mileage, more responsive driving, quieter operation and increased durability. The new transmission features a more advanced torque converter lockup clutch and is designed to work best with a new type of low-viscosity ATF transmission fluid, colored blue instead of the usual red.
Together with low-drag planetary gears, bearings and internal seals, the “FE-ATF” fluid provides less friction and improved fuel mileage. Lower hydraulic pressure and enhanced electronic software helps provide even smoother shifting.
The Mercedes-Benz Alabama Plant
Along with the M-Class, the GL-Class sport utility vehicle is produced at the Mercedes-Benz plant in Tuscaloosa, Alabama, which began production in 1997 with the first-generation M-Class. Since 2001, more than $600 million has been invested to expand the facility.
About Mercedes-Benz USA
Mercedes-Benz USA, headquartered in Montvale, New Jersey, is responsible for the sales, marketing and service of all Mercedes-Benz and Maybach products in the United States. MBUSA offers drivers the most diverse line-up in the luxury segment with 13 model lines ranging from the sporty C-Class to the flagship S-Class sedans and the SLS AMG supercar. MBUSA is also responsible for the distribution, marketing and customer service of Mercedes-Benz Sprinter vans and smart cars in the US.