Used 2015 Mercedes-Benz M-Class ML 400 4MATIC® SUV Review

For 2015, the Mercedes-Benz M-Class lineup sees greater fuel efficiency with a pair of new engines -- a smaller diesel and a turbocharged V6 -- and the fitment of fuel-saving automatic engine stop-start technology for all engines.

The 2015 Mercedes-Benz M-Class may not be a standout among its rivals in any single category, but its supremely comfortable cabin and wide variety of engines and packages gives it broad appeal.

Notably, we picked the Mercedes-Benz M-Class as one of Edmunds' Best Used SUVs and Best Used Luxury SUVs for 2015.

In the premium midsize crossover sport-utility segment there are a couple of athletic entries that feel as if they could give a sport sedan a run for the money on a deserted, curvy road. The 2015 Mercedes-Benz M-Class is not among them. But for the greater majority of people shopping for a practicality-minded luxury crossover, that will be a non-issue. It's the M-Class' roomy, inviting cabin and feeling of impenetrable build quality that hold much greater sway.

Mercedes certainly gives you a wide range of engine options to choose from. Whether you're seeking high fuel economy or high performance, this Mercedes-Benz crossover trumps its American- and Japanese-brand rivals when it comes to providing a choice of power to the people. Although the popular, gasoline V6-powered ML350 carries over, the M-Class is refreshed with a new pair of models that each comes with an equally new engine. The ML250 Bluetec and its more efficient turbocharged four-cylinder diesel replaces the old six-cylinder ML350 Bluetec diesel, while the old V8-powered ML550 gives way to the turbocharged six-cylinder ML400. Sure, these lower model numbers may be concerning to those who value the apparent prestige that comes with topping the neighbors with higher digits, but both should represent significant fuel economy gains versus their predecessors without any real noticeable drop in performance. And if a big number is ultimately what you're seeking, the wild ML 63 AMG is still available, offering as much as 550 horsepower.

Close the hood and take a seat inside any ML and it will be quickly apparent that the cabin quality, as expected of a Mercedes-Benz, is second to none. The massive selection of options allows one to tailor the ML to his or her tastes -- indeed there are no fewer than four kinds of wood trim available. The downside is that it is all too easy to pump up the already hefty price by another five figures if you're not careful while checking boxes.

Shoppers in this segment aren't exactly left wanting for good choices. The M-Class' most direct rivals are likely the BMW X5 and Range Rover Sport, which boast sharper handling and provide comparable luxury, power and features along with the option of a third-row seat, something lacking in the ML. Those third-row seats are suitable for small children only, however . If sporty performance is a top priority, the Porsche Cayenne is a breed apart, while the Acura MDX and Lexus RX 350 are also quite appealing, especially for families. But for those who prefer to cruise in dignified comfort, the 2015 Mercedes-Benz M-Class is bound to satisfy.

The five-passenger 2015 Mercedes-Benz M-Class is available in four trim levels defined by the engine fitted: ML250 Bluetec, ML350, ML400 and ML 63 AMG. All trim levels come with all-wheel drive (4Matic in Benz lingo) except for the ML350, which can also be had with rear-wheel drive.

The ML250 (replaces last year's ML350 Bluetec) comes standard with 18-inch wheels, adaptive suspension dampers, LED running lights and taillights, automatic wipers, a sunroof, roof rails and a power liftgate. Inside, you'll find dual-zone automatic climate control, cruise control, wood interior trim, a manual tilt-and-telescoping leather-wrapped steering wheel, eight-way power front seats (with four-way power lumbar adjustment), heated front seats, reclining 60/40-split folding rear seats, MB-Tex premium vinyl upholstery (leather is optional), the COMAND electronics interface (with 7-inch color display), Mercedes' mbrace2 communications system (includes smartphone app integration), Bluetooth phone and audio connectivity and an eight-speaker sound system with HD radio, a USB port and an auxiliary audio jack. There are also numerous standard safety features listed below under Safety.

The ML350 is similarly equipped but comes with 19-inch wheels standard.

Adding the Premium 1 package to either the ML250 or ML350 brings a rearview camera, power-folding exterior mirrors, auto-dimming rearview and driver-side mirrors, a 10-way power driver seat (with four-way power lumbar), a power tilt-and-telescoping steering wheel, driver memory functions, double sun visors, a navigation system, voice command functionality, a rear 115-volt household-style power outlet, satellite radio and an iPod interface.

The Sport package for the ML250/350 adds AMG exterior trim and either 19- or 20-inch AMG wheels.

The ML400 starts with the ML350 models' standard equipment and the contents of the Premium 1 package and adds a turbocharged engine, keyless ignition and entry, a 13-speaker Harman Kardon sound system, leather seating, heated and cooled cupholders, multicolor interior ambient lighting and the Lane Tracking package (blind spot and lane-departure warning systems).

There are many other available option packages. The Lighting package includes adaptive bi-xenon headlights with automatic high-beam control. The Driver Assistance package adds adaptive cruise control and an advanced version of the Lane Tracking package (see "Safety," below). The Parking Assist package adds front and rear parking sensors, an automated parallel parking system and a surround-view parking camera. The On/Off-Road package (ML350/400) includes an adaptive suspension with air springs ("Airmatic"), a two-speed transfer case, a six-mode terrain selector and underbody skid plates. Airmatic is also available as a stand-alone option.

The Convenience package features the heated and cooled cupholders, second row sunshades and a center armrest pass-through. The Interior Sport package includes front sport seats, special seat trim (simulated suede on the ML250/350, Napa leather on ML400) and a sport steering wheel. Audiophiles may want to consider the pricey but stunning 14-speaker Bang & Olufsen BeoSound audio system.

The ML 63 AMG goes all-out with a turbocharged V8, an AMG-tuned Airmatic suspension with adaptive stabilizer bars, exclusive 20-inch AMG wheels, special leather upholstery, sport seats with ventilation, and unique styling elements inside and out. The Premium 1, Lighting, Lane Tracking and Parking Assist packages are standard as well, while the Driver Assistance package is optional. The AMG Performance package raises engine output and adds a higher top speed, along with red-painted brake calipers and a carbon-fiber engine cover. Also optional are 21-inch AMG wheels along with most of the other trims' extra equipment.

Individual option highlights include the "Active Curve" handling enhancement system, a trailer hitch, a panoramic sunroof, running boards, keyless ignition and entry, three-zone climate control, "multicontour" front seats with adjustable bolsters and massage functions, ventilated front seats, heated rear seats, the heated steering wheel, a dual-screen rear-seat entertainment system, enhanced iPhone connectivity controls (Drive Kit Plus), and a Splitview display for the COMAND system that can project different images to the driver and passenger.

All 2015 Mercedes-Benz M-Class models come standard with a seven-speed automatic. 4Matic all-wheel drive is standard on all but the ML350, where it's an option that replaces rear-wheel drive.

The ML350 features a 3.5-liter V6 engine rated at 302 hp and 273 pound-feet of torque. In Edmunds performance testing, an ML350 with AWD accelerated from zero to 60 mph in 6.8 seconds, which is average for this segment. EPA-estimated fuel economy is 20 mpg combined (18 city/24 highway) with rear-drive and 19 mpg combined (17 city/22 highway) with AWD.

The ML250 Bluetec comes with a 2.1-liter turbocharged four-cylinder diesel that produces 200 hp and a healthy 369 lb-ft of torque. Fuel economy is excellent at 25 mpg combined (22 city/29 highway). Mercedes claims an 8.9-second 0-60-mph time, which would place it near the bottom of the class in terms of acceleration.

The ML400 boasts a 3.0-liter turbocharged V6 that produces 329 hp and 354 lb-ft of torque. EPA-estimated fuel economy is 20 mpg combined (18 city/22 highway). That means it essentially matches the ML350 for efficiency, but it sprinted to 60 mph in a quicker 6.1 seconds in our testing.

The ML 63 AMG rocks a 5.5-liter turbo V8 that produces 518 hp and 516 lb-ft of torque. The AMG Performance package boosts that output to 550 hp and 560 lb-ft. Mercedes says the ML 63 will hit 60 mph in a startling 4.7 seconds in standard form, while the Performance package knocks off a tenth of a second. Fuel economy stands at 15 mpg combined (13 city/17 highway).

Properly equipped, the ML250/350 can tow up to 6,600 pounds; the ML400 and ML 63 AMG can tow up to 7,200 pounds.

Standard safety features for all 2015 Mercedes-Benz M-Class models include antilock brakes, traction and stability control, PreSafe (which can identify an imminent crash and automatically take measures to secure occupants), hill-start assist and hill-descent control, active front head restraints, a driver inattention warning system, a collision warning system, front and rear side airbags, side curtain airbags and a driver knee airbag. The mbrace2 communications system includes automatic collision notification, an SOS button, stolen vehicle location, geo-fencing, alarm notification and remote door lock/unlock. A rearview camera is standard on the ML 63 and optional on all other versions.

The M-Class additionally offers two levels of blind-spot and lane-departure protection. The first level comes via the Lane Tracking package, which monitors road conditions and alerts the driver by vibrating the wheel or emitting a beep. The second level is found in the Driver Assistance package, which adds "active" versions of these systems that can selectively apply the brakes if the driver fails to heed the car's warnings.

In government crash testing, the M-Class received a perfect five stars for overall, front and side crash protection. The M-Class also came up aces in crash tests performed by the Insurance Institute for Highway Safety, receiving the top mark of "Good" in the moderate-overlap frontal offset, small-overlap frontal offset, side-impact and roof strength tests. Its seat/head restraint designs also rate "Good" for whiplash protection in rear impacts, plus the M-Class garnered a "Superior" grade for front crash prevention when equipped with the optional Driver Assistance package.

In Edmunds brake testing, a 2015 ML400 on all-season tires stopped in a slightly below-average 125 feet.

The 2015 M-Class' standard gasoline V6 engine gets fairly frisky if you're willing to take it to redline, but acceleration can feel a little pokey in normal driving conditions. That's why the ML250 Bluetec diesel version is a win-win proposition: It delivers ample usable thrust in everyday passing and merging maneuvers along with superior fuel economy. As for the other, more powerful models, the ML400 is downright quick, while the ML 63 is just nuts. If ripping acceleration is a must, AMG has an SUV for you.

From the driver seat, the ride quality is exemplary, especially when equipped with the Airmatic system, isolating occupants from both road impacts and noise. It's a reason in itself to buy this Benz. On winding roads, however, the non-AMG M-Class models (without the optional Active Curve System) feel soft and out of sorts around turns. The steering is both devoid of feel and overly light in effort. Translation: This is not a sporty SUV. The ML 63 AMG, meanwhile, delivers considerably more capable but ultimately uninspiring handling.

The 2015 Mercedes-Benz M-Class features understated interior styling that complements the restrained exterior. The dashboard is almost identical to that of the larger GL-Class, underscoring the fact that the M and GL are essentially differently sized portions of the same dish.

If you're OK with only two rows of seating, save some money and get the M-Class; if you need three rows, bring enough cash for the GL-Class. However, rival midsize luxury crossovers like the Acura MDX or BMW X5 offer the option of seven-passenger seating in a package that's similar in size to the M-Class.

To its credit, though, the M offers roomy accommodations for five and provides more second-row legroom than most competitors do. Cargo capacity measures 38.2 cubic feet behind the rear seats and 80 cubes with the rear seatbacks folded flat: solid figures for this class.

Materials quality inside the M-Class is superb, ranking right up there with any luxury SUV on the market. The standard knob-based COMAND interface works better than most systems of its ilk, providing a welcome amount of user-friendly redundancy among the control knob, dash buttons and wheel controls.