by Bob Plunkett
More muscle for a smart set of wheels.
MONTPELIER, Vt. - To pick a path through the convoluted typography of Vermont, it helps to have a native aboard for guidance. But to make headway safely through Vermont's rugged mountains, it also helps to have a sturdy vehicle capable of applying traction to all four wheels.
On a recent trek from Burlington to Montpelier, a resident guide directed us away from the sanitized pavement of I-89 and instead charted a course though Bristol and Rocky Dale, to Warren and Sugarbush, along a dusty trace cut through the heart of Vermont's scenic Green Mountains. What our native didn't mention was that the selected route traversed Lincoln Gap, a natural saddle between Mount Abraham to the north and Mount Grant to the south.
The winding trail, etched into steep slopes and littered with loose gravel on packed dirt, quickly degenerated into a driver's traction nightmare. At best, we dealt with spinning wheels. At worst, we might have sent tons of sheet metal over the barrier-free lip of this so-called road and down the mountain to certain doom.
"Don't worry," the Vermonter told a nervous driver. "You've got a powerful weapon to fight for traction."
And so we did. Armed with the new V-8-powered ML430 sport-utility vehicle from Mercedes-Benz, we enjoyed both the driving characteristics and comforts of a fine Mercedes sedan and the cargo-hauling capacity and go-anywhere attributes of a rugged four-wheel-drive wagon.
Besides a lusty flow of power, this wagon also stocked four smart wheels. Its unconventional four-wheel traction system, linked to an on-board computer, distributes power automatically to each wheel individually, or in sets of wheels fore and aft, so at any time at least one tire is able to get a grip on the road. The full-time four-wheel-drive system does not lock axles to maintain traction in slippery situations; instead it can sense a slipping wheel electronically, then send braking power to the slipping wheel and redirect power to wheels with better grip.
For rugged travel off-pavement, the system has an electronically controlled two-speed transfer case with lower gear settings -- activated by dashboard button. Couple the generous muscle of that big V-8 engine with the smart traction system, and our wagon whisked up to Lincoln Gap, spewing gravel on steep spots but always maintaining traction in safe forward progression. To wit: the ML430 took nearly all work out of this dicey passage, leaving riders with nothing more to worry about than the fit of firm seats and comforts of a refined cabin.
Developed from scratch and assembled in Alabama as the first Mercedes-Benz product ever built outside the borders of Germany, the M-Class SUV originally appeared as the ML320, rigged with a 3.2-liter V-6 engine.
This year, the new Mercedes V-8 engine slots into the Benz off-road equation under the ML430 moniker. Displacing 4.3 liters, its single-cam aluminum V-8 achieves 268 hp and 288 foot-pounds of torque across a board band from 3000 to 4500 rpm. (The 3.2-liter overhead-cam V-6, also with aluminum block and cylinder heads, maintains its strong 215-hp rating.)
The advantages of the larger displacement engine are clear-cut: enhanced strength for towing a trailer, an extra dash of exclusivity and, of course, quicker acceleration. In tests powering up from 0 to 60 mph, the ML430 measures a second faster than the ML320, breaking the tape in eight seconds rather than nine. Top speed, limited electronically, reaches only 112 mph, though.
Both V-6 and V-8 engines connect to an electronic five-speed automatic transmission which can outthink a driver. So smooth and efficient that you barely detect shift patterns, the system can determine when it's best to stay in a lower gear without initiating annoying upshifts -- as demonstrated in Vermont during the descent from Lincoln Gap, when the lowest gear was needed to retard momentum.
Both wagons ride on a chassis with twist-resistant boxed sections that create an inherently rigid platform. To that sturdy foundation, Mercedes-Benz then applies front and rear suspension subframes and rubber body mounts, for a platform that's stronger, stiffer and quieter than most passenger cars.
Then comes the unexpected: fully independent double-wishbone suspension for all wheels to further isolate the passenger compartment from lumps of the road and also set up a highly maneuverable vehicle.
Other notable mechanical features include power rack and pinion steering for better turning control, plus power-assisted disc brakes tied to anti-lock and traction control systems, along with the unique Mercedes electronic stability control program.
Mercedes' unique Brake Assist is also aboard. Brake Assist, for those not inclined to use their anti-lock brakes to their full potential, automatically applies full brake force during panic stops to shorten stopping distances by as much as 45 percent.
Safety elements extend to a strong framework of steel with front and rear crunch zones and reinforced side bracing. Dual frontal airbags and door-mounted side airbags are in place, as is a front passenger seat with the Mercedes BabySmart system, which disables the passenger-side airbags when a special infant seat is installed.
The passenger compartment looks and feels like it was lifted from the Mercedes E320 -- plush bucket seats, center console, full instrumentation, wood trimmings and a host of handy conveniences tucked into every nook. The second-row seats use a bench with bottom split about a third to one side, but three articulated backrests fold forward individually to expand the cargo bay in various ways. Also, seats will inch forward to increase cargo area or tumble to maximize space.
For hauling even more people, two folding jump seats may be installed optionally in the rear. When not used, they fold up and store against upper sides of the cargo bay. With this arrangement, the wagon increases seating capacity to seven and mimics a minivan.
The sticker price for the ML series drops 1.5 percent this year for the base ML320, which now costs $34,750 (plus $545 added as a delivery fee). The muscular new ML430 begins at $43,345 and offers options like an enormous power sunroof (made of nine separate folding sheet metal panels) called the Skyview Top for $2,395.
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