So why did Mercedes-Benz bring us all the way out to Big Sky Country (that's Montana to you city slickers) to test the new M-Class? Simply put, because that's where its heart is. And no matter how many grubby kids inhabit its backseat or how much time it spends negotiating speed bumps, or parked at the local gym or mall or plastic surgeon's clinic, it's at its best out on the open road, or on the trail.
It's been mostly that way from the start. The original Mercedes-Benz M-Class was a forerunner in 1998; along with the softer Lexus RX, the ML set a new standard for a generation of luxury SUVs and crossovers.
Evolved into something better
In its first generation, the M-Class was luxurious in a way that mass-market SUVs hadn't been. Yet it had a feel that was a little too trucky at times for Mercedes-Benz's cosseted customers. Then came the second-gen ML, which was a huge step ahead in refinememt and brought this wagon up to the standards of refinement and materials offered in other Mercedes products. Now the third generation is here, and to put it simply, it's even better. With top notch safety and tech features to complement its rich cabin, it not only performs better but is a safer, more responsible choice and one that might make getting there easier as well as more comfortable—a true luxury good for the 21st century.
Before we tell you about all the impressive electronic wizardry that makes getting there safer and easier, we should tell you what makes getting there more enjoyable. The clean-slate-new 2012 Mercedes-Benz M-Class is about the same weight as last year's model, yet there's more power all around—and, most of the time, a transmission that can make the most of it.
Mercedes-Benz never quite got its former V-6 to feel as smooth as the in-line six that preceded it in its cars, but the all-new, 3.5-liter V-6 in the M-Class is off to a great start. With 60-degree cylinder banks rather than 90-degree ones, plus an improved direct-injection system and an ignition system that can follow up the main ignition spark with smaller ones that bring more complete combustion. Overall, power is up to 302 horsepower, and torque is at 275 pound-feet, but what you should know is that the new engine feels perkier than the previous unit wherever it matters; and whether that's from a standing start or in quick passing on a two-laner, it sings up the rev range and works extremely well with the seven-speed automatic transmission.
Best with BlueTec
But by far, our favorite 2012 M-Class model is the ML350 BlueTec. If 'wafting' up to speed easily (without downshifts) on the highway, cruising effortlessly near triple digits, and getting gas mileage that won't place a frown on the faces of your more earth conscious friends are all priorities, you'll find this model the best fit, too. M-B has reworked this engine, too, to make 240 hp and 455 lb-ft of torque. It has a 72-degree configuration and a balance shaft for smooth operation; and notably, it runs at a lower compression ratio (15.5:1) than most diesels—helping to vary air volume quickly with the turbocharger. And as with the previous version, pilot injection from precise piezo-electric injectors helps smooth out the noise and the combustion process.
And the old assumptions about clatter and odor definitely don't hold true. Cruising inside the vehicle, we actually found the ML350 BlueTec diesel to be the quieter of the two powertrains; at all but idle, the diesel accelerated with a muted baritone that made the gasoline version seem almost a bit strident—especially in its upper rev ranges. What the BlueTec has that the gasoline engine doesn't is an almost uncanny ability to tap into its torque reserves without the drama of multi-gear downshifts. Nail the throttle down for a full-steam pass, and it's still very civil as the diesel whooshes to life with a rush of torque. M-B has added an acoustical windshield this time, a company official said, and that helps block even more of the diesel's noise.
We spent most of our time driving a BlueTec model with the Airmatic suspension and adaptive damping. The system includes just two ride modes, Comfort and Sport, and we found a very significant difference between the two; Comfort soaks up all but the hardest jolts, while with Sport you get a somewhat crisper feel at turn-in but the tradeoff is that you're at all times a little more in touch with the road surface.