Passing time in the Mercedes’ BlueTec |

Passing time in the Mercedes’ BlueTec

Andy Stonehouse
Special to The Vail Trail

If you happened to be one of the throngs of ATV riders who tackled the very challenging Hagerman Pass a couple of weekends ago, only to have some jerk in a Mercedes with Illinois plates spoil your achievement by rolling up like he was on a Sunday drive ” I apologize.

I was spending the day trying to really, very seriously, test the full ability of the new Mercedes-Benz ML320 BlueTec (a fancy name for the company’s new, hyperclean diesel setup) and … I got a little carried away.

So much so that after giddily romping across Weston Pass between Fairplay and Leadville, I opted to make my way to Eagle, taking the most challenging route possible.

To that end, the 11,926-foot Hagerman Pass, which follows the old railroad grade up and over some extremely banged-up roads, is not the kind of thing one should normally expose a beat-up old Honda quad to, much less a $50,000 vehicle.

I can happily report that the torquey ML320 not only mastered the pass, confounding many a dusty off-roader and more than a few drivers of highly jacked-up Jeeps, but it did it with the same grace and style as it will during the 99.9 percent of time it will normally spend on hard, flat, smooth, but occasionally snow-covered pavement.

BlueTec is Mercedes’ own attempt at creating a reasonably affordable powerplant alternative to use what, at least in Europe, is a less expensive fuel source. I’m seeing gasoline prices start to scale back down here in the Front Range (nearly $3.50 a gallon again up in Cheyenne this weekend) so, maybe, just maybe, there is hope for more affordable diesel on the horizon.

That will make the BlueTec-equipped Benzes a pretty nice option. BlueTec’s spin on things is to create an additive (“AdBlue,” with top-ups required at each servicing) that reduces the noxious nitrogen oxide emissions in diesel exhaust.

In the ML320’s case, the small filler tank (located in the back, near the spare tire) contains a mixture of water and urea that releases ammonia during driving and converts 80 percent of the nitrogen oxide into non-toxic products.

At the same time, the BlueTec engine ” an austere 3.0-liter V6, cranking out only 210 HP but a nice 400 pound-feet of torque ” generated about 26 mpg on average during my occasionally trying travels, and up to 30 mpg when cruising sensibly on highways through the Arkansas Valley.

That’s a substantial increase over the 20 mpg suggested for a very similar gas-powered and also nearly 4,800-pound ML350, so once that whole diesel price differential thing gets solved (if it ever does), the BlueTec-equipped machine does indeed make sense, as well as being “green” in its own weird way. Top it off, drive the speed limit, and you might get 600 miles out of a tank.

As for regular operations, the diesel engine was almost completely seamless. The extra whomp of torque allowed speedy takeoffs when required, and made it easy to slowly but powerfully inch my way over rocks and bumps and puddles on the way to the summit(s).

It can be a tad noisy, however. Not garbage truck diesel-style noisy, but I found that during my low-rev, 25 mph ascent of Independence Pass on the way back, there was a fair amount of clatter; noise was not an issue during regular motoring.

I drove a very similar ML550 last New Year’s but did not get the chance to try it out on exposed shale slopes and full-blown off-road stuff; I can now tell you that the basic ML package is one of the most refined and yet still totally capable machines I’ve ever taken through the rough stuff.

All of the off-road gadgetry does indeed work like a charm, from the Airmatic lift system (giving you up to 10.3 inches of clearance) to the adaptive damping system, which can both accommodate totally poised, high-speed highway driving and allow you to bounce comfortably through the ruttiest gravel roads.

M-B’s downhill speed regulator, its version of hill descent control, works on the brakes and gearing so you can concentrate on steering around paint can-sized rocks, although it did get me rolling a little too fast for comfort on occasion. At that point, I deferred to the wheel-mounted paddles to work through the seven-speed automatic transmission to lower my gait.

I must also offer a hearty recommendation to the Bridgestone Dueller on-and-off-road tires provided, which didn’t look particularly backroad-worthy, but got me through the worst.

The ML’s excellent audio and navigation system, plus an apparently 60-part information screen between the speedometer and tachometer, put you on the verge of information overload, but … you learn to concentrate on the road in those circumstances.

All of the class is there as well, from the supportive, beautifully crafted leather seating, the hardwood trim and the brilliant, AMG-derived body design to bits such as the power liftgate and a terribly complex cargo management rig.

The new pushbutton start, a large button looking a bit like something from a medieval suit of armor, does the job, but leaves you with a standard M-B key that apparently cannot actually be inserted anywhere in the car.

Odds are you will never see an ML, diesel or not, inching its way over Hagerman (or a real beast like Mosquito Pass, or over the rocks up to Holy Cross City) … but the option exists. Cross you fingers for diesel prices to scale back and it makes more sense on the regular highway, too.

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