2015
Mercedes-Benz M-Class

Knowing who you are and what you’re trying to do is a good first step in being successful. The trouble comes when your task is known, but you start off by working against yourself. For example: You need to get in shape to run a marathon, but your first decision is to buy a carton of cigarettes to smoke during your long runs. That’s trouble.

Mercedes-Benz hasn’t gone so far as to make a pack-a-day-smoker/marathoner combo with its M-Class, but there are some questionable things going on with it.

The 2015 Mercedes-Benz ML400 is a five-seat, midsize SUV that excels in offering comfort and a high-quality interior, yet misses the mark in a couple ways that left me scratching my head.

Gas-powered M-Class SUVs now include the ML350, ML400 and ML63 AMG. The ML400 we tested came with a 329-horsepower, twin-turbo 3.0-liter V-6 that for 2015 replaces the ML550 and its 402-hp, turbo 4.7-liter V-8 engine. (Also new is a turbo-diesel four-cylinder in the ML250 Bluetec, which replaces the ML350 Bluetec; the new engine is less powerful but more efficient.) The ML350 is available with rear- or all-wheel drive, but all other trim levels come only with 4Matic all-wheel drive.

Another big change: The ML400 loses more than 250 pounds versus the ML550; you can compare the full range of specs of the two cars here.

The Mercedes-Benz M-Class competes with other luxury SUVs, such as the Audi Q7, BMW X5 and Land Rover LR4, all of which you can compare here.

Exterior & Styling
The ML400 has traditional SUV styling, with an upright windshield and a roof that goes straight back to the cargo liftgate rather than curving downward, as do other vehicles that attempt to ape the lines of a coupe.

Around front, the grille and headlights are similar to other Mercedes-Benz cars and SUVs.

How It Drives
Driving the ML400 is when you start to sense that some parts of the car are working against each other. The ML400 is a luxury SUV and, as such, can be expected to have a comfortable ride. Our test model also featured Mercedes’ Airmatic suspension, a $1,610 option. Airmatic suspensions I’ve tested do an exceptional job of absorbing bumps and still offering support when you take corners. However, our test model came with optional 20-inch wheels that, while looking lovely, made for shorter tire sidewalls, which contributed to a harsher ride.

I felt at times like the ML was a bit too jittery and wasn’t absorbing bumps as well as other luxury cars with air suspensions — or even some luxury SUVs — that I’ve driven lately. I blame the wheels for that. Further, the ML400 Airmatic setup has a Sport setting, which firms up the suspension. That, combined with the larger rims, made for a very unpleasant driving experience. I felt every small ripple in the road, and my head bounced off the head restraint when I hit a larger bump.

What really irks me about the Sport setting is it’s just a suspension change: There’s no effect on the engine or transmission. You’re just hitting a button that makes the ML ride harder.

Really, if you want that higher AMG performance and a sporty ride in the ML class, upgrade to the Mercedes ML63 AMG. If you want a luxury SUV, spend $1,610 on the ML400’s Airmatic suspension, keep it out of Sport mode and don’t bother with the 20-inch rims.

The rest of the ML400’s driving experience is quite good. The steering is light but still feels connected, fitting the lighter-is-better feel usually found in luxury SUVs. I never felt like the Mercedes-Benz ML was floating along, as other SUVs can, but the steering didn’t have the feedback that the BMW X5 has.

Acceleration is very good. I worried about the decrease in horsepower versus the 2014, but it wasn’t noticeable on the road; the car’s weight loss must help with your sensation of the engine’s power. Overall, it’s got good power for passing on the highway and for merging and accelerating away from stoplights, and the engine makes a nice, snarling sound when pushed.

Finally, as a side note, the ML400 has the most unobtrusive engine stop-start feature of any car I’ve driven. If it weren’t for a light on the dash, I wouldn’t notice when the car was shutting on and off. That’s a nice touch and something everybody — but particularly luxury-car brands — should be doing.

The Mercedes-Benz M-Class requires premium gas. The ML400 gets an EPA-estimated fuel economy of 18/22/20 mpg city/highway/combined, which compares favorably to the 14/19/16 mpg that the 2014 ML550 got. Further, the ML400 with all-wheel drive gets better mileage than the ML350 with all-wheel drive (17/22/19 mpg).

Interior
The ML400 has a pretty interior in a way not many cars do. After driving the ML400 for a while, I realized it was one of the rare cars where everything — from the center console lid to the heating controls — looked and felt like it was the correct choice for the car. Nothing felt like a cheap piece left over from the parts bin, even though things like the climate control rings have the same style as other Mercedes cars.

Even the power hatch closing button on the liftgate looked nice … and I was especially drawn to it after testing a competitor’s luxury SUV offering and noticed that its rubbery button was carried over from its non-luxury brand. That’s a small thing, sure, but details set mainstream apart from luxury, and Mercedes largely nailed those small things.

It is worth noting, though, that our test model came with the optional Open-Pore Brown Ash Wood trim ($160) that looked and felt like wood — something I find to be rare in cars today — as well as a package that included heated, cooling and massaging front seats; heated rear seats; and a rear climate control zone. It all added up to more than $3,300, which is a lot of money, but the quality was worth it.

Also, the rear seats are roomy and comfortable in terms of head, leg and hip room. There’s just more room in the rear cabin area than other SUVs have, period. I found it very easy to turn around (so that my knees were on the seat) and reach behind into the cargo area. Nearly every other SUV in which I tried that maneuver made it a literal pain.

Mercedes-Benz also deserves praise for the ML’s outward visibility. It was the best SUV I’ve driven in a long time on that front. In an era of sloping roof pillars that seem designed for either a stylist or a wind tunnel, it’s nice to sit in a car in which its designers took into account the fact that someone might need to see out of the car.

That’s not to say everything in the interior is peachy: For starters, I found the silver finish on a few of the buttons to be nice, but sunlight occasionally washed out their white markings, making it impossible to tell what switch I was hitting.

Also, while the rear seats are comfortable, the only rear cupholders on our test model were embedded in the fold-down center armrest, so you could carry either drinks or three people in the rear, but not both.

Lastly, the standard interior is Mercedes’ MB-Tex vinyl interior. It was not on our test model, but it’s worth noting that upgrading to leather seats on the ML350 costs more than $1,600.

Ergonomics & Electronics
Mercedes-Benz uses its Comand system to control features such as navigation, radio and other functions. Overall, I found the system easy to use and responsive. What really helps is that there’s a simple Back button if you manage to find your way onto the wrong menu. Also, I think using a rotary knob to scroll through things such as radio stations is a smart decision.

All in all, I used the system extensively throughout my drive because it was easy to use, but there was one fairly major area that left me scratching my head: The optional seats can be adjusted multiple ways, and you can adjust the main settings — height, seatback angle, distance from pedals — using buttons on the door, but things like the lumbar and side support have to be accessed through the center media screen. That’s not the quickest or easiest way to make the adjustments, and it’s not intuitive. I felt like when I turned the dial clockwise on one setting to make the bolster more supportive, I had to turn it counterclockwise on another setting to get more support.

The only saving grace was the memory settings for the seat. Without those, I honestly don’t think I’d pay for the uber-adjustable seats. It’s just a long, fiddly process to get everything “just so.” Another editor who had time in the ML400 never learned how to change the seats at all, because it’s so hard to figure out where to go to make the adjustments.

Cargo & Storage
Interior storage — with the exception of the rear cupholders — is very good. Up front, there are multiple cupholders, a really useful indentation I used for my parking pass, plus a fairly large center console. I was not wanting for more places to put my stuff up front.

In back, the cargo area is on par with the ML-Class’ body type competitors. Interestingly, Mercedes uses an old seat-folding design, where you must first raise the seat bottom then fold the seatbacks down. (It’s not recommended to just fold the backrests and live with an uneven cargo floor.)

I’m of two minds when it comes to the seat-folding design. It’s a two-step process where other automakers have managed to do it in one, and the seatbacks are quite heavy and harder to raise back into position than those in other cars. On the other hand, the cargo area is large — easily swallowing my largest bike. Also, Mercedes was thoughtful enough to put loops on the seat bottoms, which not only made raising them easier, but also meant that I didn’t have to jam my hand down into the seat bottom — where someone else’s bottom had just been — to raise the seat.

Safety
The 2015 Mercedes-Benz M-Class is an Insurance Institute for Highway Safety Top Safety Pick Plus. To earn that designation, a vehicle must receive ratings of good or acceptable in the small-overlap frontal test; good in the other four tests; and basic, advanced or superior for frontal collision prevention features, whether those features are standard or optional.

Our test model came with a Driver Assistance Package, a $1,950 option that includes blind spot assist, lane-keeping assist and Mercedes-Benz’ Distronic Plus adaptive cruise control system, which itself includes Pre-Safe Brake, a forward collision warning system with autonomous braking. In addition, our test car also came with a $1,390 Lighting Package that includes bi-xenon high-intensity-discharge lighting with active curve lighting.

You can check out all the safety features here. Our child-safety seat tests can be found here.

The M-Class is not predicted to have good reliability.

Value in Its Class
Our test model cost $79,310 as-equipped, and that’s within the realm of what you’d pay for higher-end versions of the Q7 and X5.

What the ML400 delivered, compared with the Q7 and especially the X5, was a more comfortable ride and a prettier interior. Those competitors, particularly the X5, offer a firmer ride and a sportier driving experience. The Q7 I found to be in the middle, offering a sporty-ish, luxury-ish compromise between the polar extremes of the X5 and ML400.

People considering the ML400 would be best served by carefully considering their options. The larger, 20-inch rims are not where I’d spend my money, but I would go for the Airmatic suspension and the comfortable — if difficult to adjust — seats.

That’s because the ML400 is best when it’s clearly focused on being a comfortable, pretty, midsize luxury SUV, and I believe those options help it be that.