The petrol folks are producing diesel fuel with 97 percent less noxious sulfur so diesel-powered vehicles run cleaner.
Nine states—including the car-heavy California and New York—had adopted emission regulations so strict they effectively barred diesel sales, a hurdle the cleaner fuel helped the oil burners clear.
For 2009 Mercedes-Benz has a trio of 50-state diesel SUVs: the ML, GL and R. Each is called BlueTEC for the technology that injects a special AdBlue fluid into the catalytic converter that reduces oxides of nitrogen to the same levels as gasoline.
We tested the five-passenger ML320 BlueTEC. If you're one of those who remember 5-cent candy bars and glass milk bottles, you'll find things have changed with diesel, too, but for the good. The stink is gone. Stand by the engine or the tailpipe and there's now oil-fume stench or billows of belching smoke.
Then there's the incessant racket that ruled out conversation inside or outside the cabin. It's not totally gone in the ML, but it'sreduced to a muffled chatter.
More than one passenger expressed surprise when told a diesel was under the hood. In fact, Mercedes avoids the "d-word." It doesn't appear anywhere on the outside of the SUV.
Only time you're let in on the secret is when opening the fuel-filler door and seeing the green "diesel fuel only" warning.
But one diesel negative lingers. The sign at the local station read lead-free gas at $1.99, diesel at $2.93. The difference in a fill would be about $25. Still diesel stands out in driving range.
The ML BlueTEC is rated at 24 m.p.g. highway so that 25-gallon tank can take you about 600 miles before a refill.
The ML320 is powered by a 3-liter, 210-horsepower, turbodiesel V-6.
The turbo helps launch the 5,000-pound crossover from from the light and into the passing lane with the same ease as a gas V-6—with a slight, but noticeable, turbo hesitation.
Ride is luxury smooth. The wide-profile 19-inch radials have a big paw print to grip the road.
Our test vehicle came with optional adaptive damping with a "comfort" mode for smooth sailing over pavement or a firm "sport" mode for aggressive moves and off-roading.
On pavement, however, the latter mode transmits every ripple to the seat of your pants.
The ML320 comes with on-demand all-wheel-drive activated when detecting wheel slippage. But there's no low setting for crawling or climbing through unexplored territory.
When off-road or in deep snow, a dash button raises the vehicle several inches.
Stability control with traction control is standard to keep the vehicle going in the direction pointed. Four-wheel anti-lock brakes and side-curtain air bags are standard, too.
An interesting innovation is Pre-Safe, which can tell a collision is impending, using sensors that monitor steering angle, braking pressure and deceleration. Launched on the premium S-Class sedan, Pre-Safe automatically tightens front seat belts and moves the front passenger seat in position for optimum protection from front air bag and side curtain. If it senses a rollover, the sunroof also closes.
A new-for-2009 Comand system features a large color screen with an in-dash, six-disc CD changer and a Bluetooth interface for hands-free phoning. Comand can be equipped with an optional iPod/MP3 interface, Sirius satellite radio, HD radio, voice-control system and navi system with real-time traffic info. Mastering the controls takes practice and patience. Lots!
The cabin has good stretch room for people and all their limbs. Cargo space is huge. Rear seats fold flat if you need a massive amount.
Couple gripes include the first-aid kit in the rear cargo wall. Why out of reach? And when in the down position, rear-seat headrests bite passenger backs, which may be why first-aid is needed.
The ML320 BlueTEC starts at $48,650 but tops $50,000 quickly with options such as the $6,600 premium package with Comand control, navi and power liftgate.
The diesel ML runs about $1,500 more than the V-6 gas ML, whose m.p.g. rating is only 15/20 so diesel goes about 100 miles more on a tank.
Those who pay $50,000 for a BlueTEC are doing their part to conserve fuel—without standing in line for batteries.
Read Jim Mateja Sunday in Rides. Contact him at rides@tribune.com.
