The following review is for a 2012 Model Year. There may be minor changes to current model you are looking at.

All-new third-generation version smoother and better.

Introduction

The 2012 Mercedes-Benz M-Class is all new, with ML350 4MATIC gasoline and ML350 BlueTEC 4MATIC diesel versions available. 

Mercedes-Benz invented the luxury SUV, with the 1998 ML320. Now comes the third generation, with a new 3.5-liter engine. The '98 ML320 made 215 horsepower and got 17/21 miles per gallon, according to the NewCarTestDrive.com archives. 

By comparison, the all-new 2012 Mercedes-Benz ML350 makes 302 horsepower and gets 17/22 mpg. That's substantially more power without sacrificing fuel economy. Using the Consumer Price Index, today's ML350 costs about 10 percent less than the comparable model did in 1998. The 2012 ML350 has technical capabilities, features and quality that the 1998 model only dreamed of. Too much to list, as they say. 

The 2012 ML350 third-generation model is about the same size as the 2011 second-generation version. Made in Alabama, the 2012 ML350 is 1 inch longer, 0.5 inch wider, 0.75 inch lower, and 22 pounds heavier than the previous model. 

The 2012 ML350's new 3.5-liter direct-injection V6 is smoother, more powerful, and more fuel efficient than the 2011 version. It's mated to a new 7-speed automatic transmission with paddle shifters. We found the new 3.5-liter gas engine exceptionally smooth, and it provides rapid acceleration. The new 7-speed automatic is sweet, at least until you try to tell it what do. 

The new ML350 looks lower and wider, even though the eye can't discern those fractions of an inch. Designers have added distinctive and powerful styling to the front and side views. Muscle-car hood. The back isn't bad but it could be a Kia. 

The M-Class interior has been upgraded for 2012 (and it's not easy to upgrade a Mercedes interior). The seat cushioning is just right. More bolstering would be helpful going around corners, but lower bolsters are easier for getting in and out and for unloading children. The standard MB-Tex upholstery is as good as leather, but the optional stitched black leather is elegant. Walnut touches come standard, and aluminum trim says class. The ML350 is extremely quiet inside. The interior is well laid out and the rear seat is roomy enough. 

The standard equipment list for 2012 is long, longer than last year, but the options list is eye-opening. You can spend many thousands of dollars in options, and might need to, to get the equipment a Mercedes is expected to have. 

It's designed to be extremely safe, with nine airbags, crumple zones and steel-reinforced cabin, and it has a sensitive Electronic Stability Program. But we noted a big blind spot over the driver's right shoulder, caused by the C-pillar. 

The ride is totally smooth. We tried and tried, on Montana back roads including gravel, to find a bump the suspension couldn't smooth out, to no avail. The ride is solid, steady and comfortable in every situation. The ML350 doesn't like fast or quick cornering, not even with the $5,150 Dynamic Handling Package. 

All 2012 ML350s come standard with 4Matic all-wheel drive. The sophisticated AWD system maintains a 50/50 torque split on dry pavement, but can send 100 percent of the torque to one wheel, if necessary. Three wheels deep in mud, one on dry land, and the Benz should drive right out. 

The ML350 BlueTEC features the latest diesel technology, with a 3.0-liter V6 diesel engine making 240 horsepower and a gigantic 455 pound-feet of torque at 1600 rpm, rated for towing up to 7200 pounds, same rating as the gas engine because of the chassis, but with far less engine effort. The BlueTEC is estimated at 20 city and 25 highway mpg. 

The BlueTEC model has everything in common with the ML350 4Matic except the engine, which makes it feel like it has nothing in common. Everything happens slower in the BlueTEC, making the vehicle feel stodgy. The ride is as smooth, but acceleration isn't. Redline is 4200 rpm instead of 6200, the transmission shifts at different times, and slower. The BlueTEC is high-tech diesel and old-school Mercedes, nothing wrong with that. 

Lineup

The ML350 4MATIC ($49,865) uses the new 3.5-liter V6, and the ML350 BlueTEC 4MATIC ($51,365) uses the 3.0-liter V6 diesel. Both come standard with power everything, from sunroof to liftgate, leather-like upholstery and wood trim, Bluetooth, 7-inch display screen, shift paddles, LED taillamps, aluminum roofrails, and 19-inch alloys. 

Standard safety equipment includes nine airbags, ABS with brake assist, ESP, LED daytime running lights and taillamps, tire pressure monitor, ATTENTION ASSIST, and ADAPTIVE BRAKE. 

Available safety equipment includes a Lighting Package ($1290) with bi-Xenon headlamps, adaptive high beam assist, and corner illumination; Lane Tracking Package ($850) with blind spot assist and lane keeping assist; and Driver Assistance Package ($2950) that turns the warnings active, and at speeds below 45 mph will apply the brakes when you're headed for a crash: 2.6 seconds before impact it beeps at you, at 1.6 seconds it applies 40 percent of the brakes, and at 0.6 seconds it slams them on. 

Walkaround

The new 2012 ML350 looks hot in black, wider and lower. There's distinctive and powerful styling to four-fifths of the ML350, the front and side views. You know it's a new Mercedes. The back isn't bad but it could be a Kia. 

With a long wheelbase, high beltline and short overhangs, the ML350 looks stylish from the side, especially in black (silver loses something). Stainless steel trim accentuates the line. Mercedes brags about the chrome door handles, we say who needs 'em. 

Notes say: lots of funkiness, cool black teeth in grille, black chicken wire in nose, powerful sculpted hood with intakes, muscular headlamps, roof vents, big chrome skidplate wraps under chin, cheesy running boards, side sculpting BMW-like, steep rear slope, spoiler, rear chrome skid plate. 

Interior

The view through the windshield of the M-Class isn't expansive to match the grandeur of the car, but meanwhile front seats aren't crowded by the dash. 

The instrumentation is pretty and well-designed, in aluminum not chrome. Big 7-inch screen at the top of dash, bordered by swiveling vertical HVAC vents. Climate control has a bunch of buttons; other cars make just three work. Not too many steering-wheel controls, but transmission paddles bigger than necessary for sport shifting. 

Wide center console with good cubbies, including well-placed coin holder. It's deep but not long. Heated and cooled cupholders, how cool is that! Big door pockets. Not much rear seat legroom, but enough. 

Big blind spot! A sacrifice to looks, as it's a result of the C-pillar that Mercedes didn't want to change, thinking it's the visual identity of the M-Class. Rearview camera is optional; we recommend getting it. 

Optional panoramic roof doubles the size of the sky. Optional DVD system gives rear passengers even more to look at. Optional iPod docking station gives them more to do. 

There are eight stainless buttons for radio and navigation on the center console, with unpainted etched icons that are almost impossible to see; why isn't the etched part painted? Feels like sloppy work. The optional navigation system was problematic, freezing twice in four hours. 

The cruise control stalk has been changed, after 15 years of people complaining that the car sped up when they bumped the lever while turning left. Now it's not so easy to engage by mistake. 

Driving Impression

The new engine is exceptionally smooth, while being powerful at 302 horsepower. It's aluminum, a narrow 60-degree V6, while most V engines are 90 degrees. The acceleration is excellent, you don't need more than this; engine is mated to a mechanically sweet new 7-speed automatic transmission. 

Driving casually, the transmission is so smooth you forget it's there. The transmission is less sweet in manual mode, where it gets disobedient. It refuses to short-shift, upshift with moderate throttle at low rpm, or when the throttle is backed off. 

The ride is smooth like the acceleration. We tried and tried, on Montana back roads including gravel, to find a spot the suspension couldn't handle, to no avail. The ride of the ML350 is solid, steady and comfortable in every situation we could find. 

The ML350 doesn't like fast or quick cornering, though. Despite its new active rear anti-roll bar, part of the Dynamic Handling Package that our ML350 came with, also including active damping, air suspension, and 20-inch wheels with all-season tires. We pitched the ML350 into some twisties, and it responded with insecurity and reluctance to track true. 

Maybe it's the new active electro-mechanical steering, and not the suspension or the $5150 worth of dynamic handling. The active rear anti-roll bar is split in the middle, and adjusts according to the needs of separate rear wheels; theoretically it eliminates body roll, but you won't hear us say that. 

All ML350s are 4MATIC, or all-wheel drive (another thing you didn't get in 1998 for $54,824 of today's dollars). The sophisticated system stays at 50/50 on dry pavement, but can put 100 percent of the torque to one wheel, if necessary. With three wheels in mud, one on dry land, the Benz should drive right out. 

We weren't able to test that, but we got great seat time off-road, and we were pretty much dazzled by the ML350's performance on Montana gravel and dirt roads. We wanted to drive it like a rally car, but the ESP wouldn't allow it. It was highly intrusive, shutting down the throttle at the mere hint of a slide. 

The pre-tensioning seatbelts became a drag, too. We were hardly sliding at all, and the car kept shouting: We're gonna crash, we're gonna crash! So the belts kept strangling us at the chest. 

It was amazing how the chassis smoothed out the bumps, whether in Comfort mode, or Sport mode with raised air suspension in the Dynamic Handling option. We found a rocky and rutty fire trail, and the big Benz just laughed. 

We locked the brakes to test them on the gravel, and the stops were quick, true and drama-free with ABS, even at 50 mph. We ran hard for the final few miles on twisty downhill pavement, and the brakes smelled hot but didn't fade. 

Our ML350 had the Driver Assistance Package, which includes a Active Blind Spot Assist that like all of them was flawed by false alarms, and Active Lane Keeping Assist, which keeps you from drifting across lanes or off the edge of the road, by vibrating the steering wheel and applying the brakes selectively to one side of the car to correct the motion. It too was flawed by over-reaction. True, if you're falling asleep and drift toward the edge of the road it might save your life; but the rest of the time the problem is it keeps trying to save you before you fall out of the boat. 

But you don't have to pay extra just to be warned. Standard safety equipment includes ATTENTION ASSIST (their caps). There's an icon of a coffee cup that lights up while a message suggests you get off the road because you're weaving. Sensors measure 'erratic steering corrections.' Those sensors are tough. If you weave just once you're marked as a possible drunk or dozer. And guaranteed, you will weave more than once, trying to work all the stuff on the console with the display screen and that mouse-like thing that they all claim isn't distracting, for example while tuning, searching, selecting and inputting any of things you might do using the COMAND System that comes with the Premium 1 package. 

Driving the diesel-powered ML350 BlueTEC version revealed it has everything in common with the regular ML350 except the engine, which makes it feel like it has nothing in common. Before you go ML350 shopping, know your needs. We'd say that towing is the only reason to buy the diesel, good as it is. It only gets 3 miles per gallon more than the gas engine, costs $1500 more (which isn't much for 3 mpg). But it gives up excitement. 

Basically, everything under the hood and in the cabin just happens slower with the BlueTEC, and makes the vehicle feel less nimble. The ride is as smooth, but the acceleration isn't. Redline is only 4200 rpm instead of 6200, but the powerband is so broad and there's so much torque (455 foot-pounds at 1600-2400 rpm) that the transmission could be a 3-speed and still work. For some reason, the transmission sometimes surged during slow shifts with the diesel engine. 

Summary

The redesigned Mercedes ML350 offers a new 3.5-liter V6 engine, 7-speed paddle-shifting transmission, sharper exterior styling and a luxury interior. The engine is super smooth while being more powerful and fuel efficient, and the ride is superb in all conditions. It struggles to remain precise when it's being pushed on twisty roads, but few heavy SUVs can do better. The ML350 BlueTEC model with the diesel engine slows everything down, while offering 3 more miles per gallon and monster torque for towing. 

Sam Moses filed this NewCarTestDrive.com report. 

Model Lineup

Mercedes-Benz ML350 4MATIC ($49,865); ML350 BlueTEC 4MATIC ($51,365). 

Assembled In

Tuscaloosa, Alabama. 

Options As Tested

Black leather ($1620), Iridium Silver paint ($720), Premium 2 Package ($5050), Active parking assist ($970), Multi-function steering wheel ($590), Dynamic Handling Package ($5150), Lighting Package ($1290), Panorama Sunroof ($1090), Heated/Active Ventilated front seats ($570), Trailer Hitch ($550), Stainless steel running boards ($670), Rear Seat Entertainment ($1970), Driver Assistance Package ($2950).