It's far from a perfect system and it's starting to show its age, but the Mercedes-Benz Comand system present in the M-Class is competent and fairly easy to live with. There are a ton of options available to bend the computer to your will. Don't like the 3D buildings? I didn't, so I turned them off. Don't like using the Comand three-tier interface? Well, there are physical buttons that quickly jump among the different infotainment modes right there on the dashboard. More so than any other infotainment system that I've tested, the Comand setup simply takes a lot of getting used to.
Performance and safety
It's worth taking the time to get used to Comand, because the rest of the ML550 is rather good. Under its hood is a 4.6-liter, bi-turbo V-8 engine that outputs 402 horsepower and 443 pound-feet of torque. That power exits the engine by way of a seven-speed automatic transmission to a full-time all-wheel-drive system dubbed 4Matic. Acceleration from a stop isn't what I'd call dramatic. The ML550 won't snap your neck, but it will hold you firmly against its optional $1,620 black leather seats. There's an obvious strength, but the big Benz isn't trying to hurt you with it. If you've ever done a 0-60 run in a Rolls-Royce Phantom, you'll know exactly what I'm talking about. (OK, maybe that was a bad example.)
But the ML550 isn't only about straight-line speed; there's also a lot to be said about the tech built into making this SUV turn. For example, there's the adaptive power steering that is so light that it can be steered around a parking lot with just one finger, but firms up as you gain speed so it doesn't feel ponderous and twitchy on the highway. There's the Agility Control adaptive suspension system that lets the ML550 soak up bumps and jolts despite rolling on 19-inch wheels but still control its body roll when asked to corner. Don't get too crazy around those twisties, though -- as good as M-B's engineers are, they're not "defy the laws of physics" good. Push it too hard and the 550 will understeer like the nearly 5,000-pound SUV on all-season tires that it is. She's a cruiser, not a carver.
The M-Class comes standard with a number of around-town driver-aid features, including downhill speed regulation and an adaptive brake system that automatically dries the rotors when driving in wet weather, assists on hills by holding the brakes for a few seconds, precharges to reduce reaction time when lifting quickly off of the accelerator, and uses a Brake-Hold feature that lets you relax your feet at long stoplights without worrying about the vehicle creeping forward until you hit the gas pedal. Also standard at this trim level is Mercedes' Attention Assist system, which monitors your behavior for signs of drowsiness and warns with a light and audible chime that you should probably take a break from driving.
Users who want a bit more help at highway speeds can opt for the $850 Lane Tracking Package, which adds Blind Spot Monitoring and a Lane Keeping Assist that vibrates the steering wheel when you cross lane markers without signaling first.
If there's one place that the ML550's performance suffers, it's at the pump. It has an EPA-estimated 15 city and 20 highway miles per gallon, but we averaged only 16.2 mpg despite our best efforts to keep a light pedal foot, and a test cycle that was nearly 50 percent freeway cruising. Potential M-Class buyers interested in maximizing their mpgs should take a look at the 550's sibling, the ML350 Bluetec. This 3-liter turbodiesel-powered model bumps the fuel economy up to 20 city and 27 highway mpg while still netting 455 pound-feet of available torque, meaning that it's green (or is it blue?) but also no slouch in the acceleration and towing capacity departments.
The ML550 starts at $57,590, but our tester adds Palladium Silver paint ($720), black leather seats ($1,620), the P01 tech package ($3,600), and the Lane Tracking package ($850). Add $225 for a heated steering wheel, $550 for a trailer hitch, and a $875 destination charge to reach our as-tested price of $66,030.
Judged against its competitors (other 400-plus-horsepower SUVs with an emphasis on Sport) the ML550 compares favorably. True, an Infiniti FX50 S has it beat on cabin tech, but Benz builds an arguably nicer vehicle around its dashboard. Porsche may slightly outperform the ML550 with its Cayenne S model, but the M-Class costs thousands less when comparably equipped. (Who'd have thought I'd live to see the day when a Benz was a bargain?)
Actually, the model that probably competes the best with the ML550 is its diesel-powered sibling, the ML350 Bluetec. For a starting price that's about $7,000 less than the gasoline-powered model, you get more torque and better fuel economy. Sure, there's a slight drop in horsepower, but even I was unable to feel a difference in performance between the two models. Besides, if you were really after the best driving performance from a big SUV, you'd be looking at the 518-horsepower ML63 AMG and its competitors. (You'd also be a bit daft, but that's just my opinion.) So, just save the money and get the diesel.
|Model||2012 Mercedes-Benz ML550 4Matic|
|Power train||4.6-liter, bi-turbo gasoline V-8 engine, 7-speed automatic transmission|
|EPA fuel economy||15 city, 20 highway, 17 combined mpg|
|Observed fuel economy||16.2|
|Navigation||Comand voice-activated navigation available|
|Bluetooth phone support||Yes|
|Disc player||DVD video and audio|
|MP3 player support||Analog 3.5mm auxiliary input, USB connection, iPod connection, Bluetooth audio streaming|
|Other digital audio||SiriusXM Radio, CD/MP3|
|Audio system||Premium audio available, not equipped|
|Driver aids||Rearview camera, cruise control (nonadaptive), Blind Spot Monitoring, Lane Keeping Assistance|
|Price as tested||$66,030|