The 2015 Mercedes-Benz M-Class is available in four different models: the ML350, ML250 BlueTEC diesel, ML400 and high-performance ML63 AMG. The ML350 is standard with rear-wheel drive, with optional 4MATIC all-wheel drive, while 4MATIC is standard on the rest of the range. The ML350 comes with a 3.5L, 60-degree V6 with high-pressure direct injection, which results in 302 horsepower. The ML250 BlueTEC features a 2.1L turbocharged diesel 4-cylinder that delivers 200 horsepower and an impressive 369 foot-pounds of torque. The ML400, meanwhile, benefits from a 329-horsepower turbocharged 3.0L V6, while the ML63 moves courtesy of a hand-built 5.5L twin-turbocharged V8 making 518 horsepower and 516 foot-pounds of torque. All M-Class engines are mated to a 7-speed automatic transmission with paddle shifters. The ML250 BlueTEC includes special electronically adjustable hydraulic engine mounts that make the driving experience far smoother than virtually any other diesel. The ML63 AMG will run from 0 to 60 mph in just 4.6 seconds, with a top speed of 174 mph. It comes with details such as a carbon fiber engine cover, painted brake calipers and a special steering wheel. The M-Class models have only two rows of seating and can accommodate up to five adults. They're packaged much like other SUVs, which is to say that rear seatbacks fold forward -- along with the lower cushions here -- to expand the cargo space up to 71 cubic feet. When the center position of the back seat isn't being used, there's a fold-down center armrest and cupholder. All four outboard positions in the M-Class are excellent and supportive -- contoured for adults and comfortable enough for all-day travel. Upholstery is available either in a combination of MB Tex synthetic and a microfiber or in leather. Ride quality of the M-Class is smooth, quiet and absorbent, yet steering response is quite sharp. Among the M-Class' many active and passive safety features offered are Lane Keeping Assist, Blind Spot Assist, a Night View Assist night-vision system with pedestrian detection, Distronic Plus adaptive cruise control, a Pre-Safe Brake system that will help brake if a collision is anticipated and a special lighting package. Attention Assist studies patterns in the driver's fine steering adjustments, can identify fatigue and drowsiness, chiming and flashing a coffee cup icon on the instrument panel. Mercedes-Benz' COMAND screen-based interface is standard, including a 7-inch display, Bluetooth audio and hands-free calling, cover-art display, a USB port and a 6-disc changer. Meanwhile, the instrument cluster has its own reconfigurable, 4.5-inch display. With the Premium I Package, a navigation system with 3D city models and Sirius traffic and weather integration is included. A special dealer-installed iPad docking station also lets an iPad integrate with the audio system.