The fully automatic and filtered climate control system uses a large-capacity air conditioning compressor under the hood and six temperature sensors in the cabin to provide efficient and accurate air temperature and flow. Theoretically, that is. We suspect there's some German over-engineering here. For example, in automatic mode, the blower speed is determined by, among other things, a photo diode that measures sunlight on the dashboard. The default temperature setting is 72 degrees. To change it, refer to your 320-page hardcover owner's manual.
You don't have to use the automatic mode, however. There are three big dials to adjust manually. Rings around the circumference of the dials are used to set fan speed, temperature and air direction, but they lack separate settings for each side of the forward cabin. The rear console (with two cupholders) allows back-seat passengers to set their own air speed and flow direction, but not temperature. The rear seat has an automatic setting, too, meaning sunlight on the dash affects blower speed in the back seat. That's high technology at work.
Mercedes' Modular Control System includes the audio controls, and those for the navigation system if the vehicle has it, displayed on a console screen. The on-off/volume button is so small it will be difficult to grip with gloves in winter. There's another small button for both tuning the radio and setting the navigation, which works like a teensy joystick. You can preset 10 radio channels from a keyboard, but there's a learning curve to mastering the system. We've never figured out how to run the navigation system without the radio stepping in uninvited, for example.
There are four power ports in the cabin, front and rear. There are storage compartments all over, though we couldn't find a good place for toll change. We like the grab handles over each of the four doors, although climbing out isn't very difficult, as the door sills sit only 18 inches above the ground. That's a low step-in height by SUV standards.
The seats are firm and relatively flat. We think they could use more side bolstering, especially for the cornering that the ML500 invites. The leather upholstery is thick and sturdy. The seats are wide, though much smaller than those in a Cadillac Escalade, and the driver sits tall above the pavement. The high seats, expansive glass, effective mirrors and fall-away hood combine for decent visibility in all directions and a secure feeling at the wheel. The rear center headrest is a great idea when five passengers are aboard, but it impedes rearward vision.
The rear seat is one of the best in the sport-utility business, though Mercedes has eliminated one of its slicker features. Where it was once three individual buckets that could be folded separately to optimize passenger or cargo space, it's now a more conventional 60/40 split. The seat bottoms are still wide and supportive, and the seats slide about five inches fore and aft, increasing either legroom or cargo space. The optional third-row seats ($995) are best suited for those 12 and under. They can be stowed away to the sides or removed altogether to take full advantage of the cargo area.
With a maximum 81.2 cubic feet of cargo space, the M-Class has more than many mid-size sport-utilities, including the BMW X5 and Infiniti FX, but less than full-size luxury competitors such as the Lincoln Navigator and Cadillac Escalade. The cargo floor is not perfectly flat behind the rear seats, which can make loading some objects more difficult.
Completely filling the large pocket in the passenger door is a leather packet with all the ML500 printed materials, including that 320-page hardcover operator's manual. Mercedes is not alone in the automotive world in its presumption that anyone who spends this kind of money on a vehicle will learn how to operate it, but mastering the controls will take a lot of learning. Another presumption might be that anyone who spends $50,000 on a vehicle will expect to have its operation made easy for them with simple or at least intuitive controls. In some respects the M-Class suggests that sophistication without complication is a conundrum. Next Page