GREENOUGH, MT – Many years before the term “Carmageddon” warned of an epic traffic jam in southern California, it could have referred to a trend that was sweeping through the ranks of luxury auto makers.

Purists figured the end was near when BMW, Lexus, Audi, Lincoln, Cadillac, Volvo and later on Porsche decided their car-only portfolios needed something more in the way of utility and off-road capability.

It all started with Mercedes-Benz and the M-Class, which went on sale in September 1997 (codename W163) with great fanfare, produced in a shiny new plant outside Tuscaloosa, AL.

The market hasn’t been the same since.

Porsche, for instance, sells nearly as many Cayenne cross/utility vehicles as it sells cars – that’s 911, Cayman, Boxster and Panamera, combined. The X3 and X5 CUVs are among BMW’s four best-selling vehicles. The Cadillac SRX CUV is threatening the CTS for top-selling honors within the brand this year.

Car loyalists might consider luxury utes an affront to civilization, but CUVs and body-on-frame SUVs can be incredibly profitable (especially when produced domestically), and the suits can’t be blamed for wanting part of the action.

And Mercedes-Benz, the German giant that made it OK to capitalize on America’s emerging interest in spaciousness, versatility and a high seating position, arrives in September with an all-new M-Class destined to uphold both its legacy and place in the market.

What makes the new ML special are two new or significantly improved engines; advanced suspension controls to enhance ride and handling; upgraded interiors; and acute attention to chassis engineering.

The M-Class has never been a repository for warmed-over technology, and this latest generation carries on that tradition.

But at first glance, the ’12 ML350 and diesel ML350 BlueTEC don’t appear to be significantly different from their predecessors, based on the second-generation M-Class that arrived in 2005 (codename W164).

The new model (W166) picks up the identical design of the tapered C-pillar and applies a similar beltline that descends toward the front. The shape of the greenhouse and roofline and raking of the windshield and side windows appear to be unaltered.

Changes to the front end would be considered subtle, if not for the smoother 3-bar grille replacing three large perforated slats in the old ML. The new grille is slightly more shallow, but the tri-star emblem remains in the same location – smack in the middle.

The new “eagle-eye” headlamps also are more dramatic, narrow and angular and integrate stylish amber light bars. LED daytime running lamps are packaged within the bumper. The new wheel wells are smaller and less flared and hug the handsome standard 19-in. alloy wheels much more tightly than the previous body style.

From the back side, the ML looks completely new and much more sporty, thanks to a clever bumper design and brushed-aluminum skid plate that hide the dual exhaust. The backlight is angled more steeply, and the beltline flows neatly around the back.

The sheet metal on the liftgate is less bulbous and now is creased in just the right places to lend a clean, horizontal design that nicely frames LED taillamps that wrap tightly around the corners.

Under the hood, Mercedes offers two engines that perform admirably: an all-new 302-hp 3.5L direct-injection gasoline V-6 and 240-hp 3.0L BlueTEC turbodiesel, available in all 50 states.

No hybrid is in the plans, although the ML450 Hybrid was available previously. The potent 4.6L BiTurbo V-8 will be offered in 2012.

’12 Mercedes ML350 4Matic
Vehicle type Front-engine, AWD, 5-passenger CUV
Engine 3.5L 60-degree DOHC DI all-aluminum V-6
Power (SAE net) 302 hp @ 6,500 rpm
Torque 273 lb.-ft. (370 Nm) @ 3,500-5,250 rpm
Bore x stroke (mm) 92.9 x 86.1
Compression ratio 12.0:1
Transmission 7-speed automatic
Wheelbase 114.8 ins. (292 cm)
Overall length 189.1 ins. (480.3 cm)
Overall width w/ mirrors 84.3 ins. (214 cm)
Overall height 70.7 ins. (180 cm)
Curb weight 4,753 lbs. (2,156 kg)
Base price $48,990
Fuel economy 18/28 (13-8.3 L/100 km)
Competition BMW X5, Cadillac SRX, Lexus RX, Audi Q5, Lincoln MKX
Pros Cons
Diesel’s way to go Gas V-6 short on torque
Wood trim makes impression Dated HMI
Exterior styling right on German engineering expensive

Both gas and diesel V-6s are more powerful and fuel-efficient than their predecessors and integrate new technology. So the question ultimately is: which is better? Whether accelerating hard on an uphill grade to pass a gravel hauler or cruising steadily along, both engines get the job done well. Both are amazingly smooth and quiet, yet responsive and emotive when pressed into service, and can sprint from 0-60 mph (97 km/h) in 7.3 seconds.

But having spent the majority of our time driving the diesel on highways and 2-lane roads that weaved through the Rocky Mountains and the Continental Divide, the diesel is better for four reasons:

  • It clobbers the gas engine nearly 2-to-1 in available torque, which is what matters most to drivers. Its 455 lb.-ft. (617 Nm) peak arrives early, at 1,600 rpm and holds on until 2,400 rpm. Dialing up 120 mph (193 km/h) on a remote Montana highway is no problem at all.
  • The new gas engine is sophisticated and all, but the bottom-line output is not all that impressive on paper, at 302 hp. Engines of similar size in less-expensive vehicles made that much, or more, several years ago.
  • DCombined fuel economy comes in at 22.5 mpg (10.4 L/100 km) for the diesel and 19.5 mpg (12 L/100 km) for the gas V-6. During a 181-mile (291-km) loop, we averaged 23.5 mpg (10 L/100 km) with the diesel, according to the trip computer. It’s worth noting diesel fuel is priced currently in line with premium unleaded gasoline.
  • 3If the ML truly is being used as Mercedes intended – for road trips and adventures and hauling lots of stuff, maybe even a small trailer – the diesel will handle the load more capably. As a low-miles grocery getter, the $1,500 premium for the diesel is probably wasted money, so the gas V-6 would be better.

With either engine, an excellent 7-speed automatic transmission (carried over from the previous ML) sends power seamlessly to all four corners via 4Matic all-wheel drive, which has been standard on all three generations of M-Class.

The transmission integrates a new torque converter with an advanced lock-up clutch and improved damper de-coupling for better fuel efficiency.

Understanding the 4-wheel independent suspension offerings requires total concentration, although the basic setup carries over: double-wishbone geometry up front and 4-arm multi-link at the rear.

Upgrading to the optional Dynamic Handling Package costs $5,150 and includes AirMatic air suspension, which uses air bladders instead of coil springs, as well as air springs, to lower the vehicle at high speeds for better handling.

Off-road, the suspension can be switched to raise the vehicle about 3 ins. (7.6 cm) for more ground clearance.

The package includes an adaptive damping system that can change compression and rebound damping every 0.05 seconds in adjusting to road conditions. The driver can switch between a “sport” setting for a firm ride and “comfort” for more compliance.

Another feature of the air-suspension package is the new Active Curve System, which uses electronic sensors, an engine-driven hydraulic pump and electronically controlled hydraulic valves to reduce body lean.

The stabilizer bars with this package are “split” in the center and connected to rotary hydraulic actuators that are inactive when the vehicle is traveling in a straight line.

In curves, the actuators are pressurized to counteract lateral pitching, reducing the natural tendency for the body to lean in curves.

With so much going on within the suspension, it’s hard to tell which feature is doing what, even while paying close attention. Suffice to say the ML stayed firmly planted during our highway jaunts, but we did not experience the base suspension.

An On & Off Road Package will be available next year that uses six transmission modes to optimize driving dynamics.

The M-Class also is the latest in a long list of newly launched vehicles to use electric power steering. The electro-mechanical rack-and-pinion unit integrates speed-dependent power assist and enables fuel savings by requiring electrical power only when the wheel is turned.

The steering feel is precise, firm and comfortable, whether on the highway or in parking maneuvers.

The interior of the M-Class reflects iterative rather than wholesale changes. There’s more real-wood trim (eucalyptus or burl walnut), colors are richer and the 7-in. (17.7-cm) central display screen has been moved up in between two air vents, rather than below them in the old model.

Cupholders have been reconfigured; seats offer better bolstering; and air vents now are square or rectangular instead of round.

But the overall layout of controls, switches and gauges is virtually identical to that of the outgoing model. Fit-and-finish in the pre-production models evaluated was excellent.

Three adults fit comfortably in the back seat, which folds flat to make room for loads of cargo.

The previous interior wasn’t so bad, and Mercedes was right not to rip it up.

What’s not to like about the new ML?

The Comand human-machine interface is not very reconfigurable and can’t display both audio and navigation information simultaneously. This HMI has been in Mercedes vehicles for several years now and feels dated at a time when consumer electronics change every month.

Adaptive cruise control is not standard, neither are cooled front seats or heated rear seats. Heck, the Hyundai Elantra is a third the price and offers rear heated seats.

Which brings us to pricing. The M-Class might be priced competitively against the X5, but the SRX and Lexus RX remain better values. The cheapest model at the media event here stickered at $56,825; the most expensive was $77,115.

Value-conscious buyers, even at this level, are paying attention. Through the first six months, the RX and SRX, respectively, are the best-selling vehicles in Ward’s Middle Luxury CUV segment.

No.3 is the X5, which received a facelift last year, followed closely by the M-Class. Not bad for a vehicle at the end of a 6-year cycle.

The X5 offers an optional third row, but M-Class does not – yet. It’s in the works, Mercedes says.

Job One in Alabama for the new M-Class, which is exported worldwide, was July 20, and Mercedes marked the occasion by announcing a $2 billion investment to expand for the launch of the next-generation GL CUV, as well as the C-Class sedan, which begins assembly in 2014.

Admittedly, the level of excitement about a new M-Class is a rung or two below that generated by a new Mercedes SLK roadster or CLS 550 4-door coupe.

But the M-Class is the third best-selling vehicle in the Mercedes stable and deserves recognition.

After all, in the world of luxury CUVs and traffic jams, “Carmageddon” hasn’t been all that bad.

tmurphy@wardsauto.com