1600 rpm. That's when you really feel it. The smooth, quiet wave of torque is akin to that of a TGV train pulling from its platform. With gusto like this, you'd think the 3.0-liter turbodiesel V-6 and seven-speed gearbox in this 2013 Mercedes-Benz ML350 Bluetec were meticulously assembled by Michael Kubler (Google him) in Affalterbach. The pull is immediate and addicting, and in a 5000-plus-pound all-wheel-drive SUV, it's downright bitchin'.

I swiftly adapt to all 455 lb-ft at my command. When passing 87 octane-drinkers on the highway, for example, the 240-horsepower ML sails past nonchalantly as if it gained a miraculous 20 mph tailwind. The intuitive automatic transmission knocks off one, two, even three downshifts to properly exploit the all-aluminum mill's muscle. In a few seconds, I'm doing speeds that could get me points on my permanent record. And there's hardly any audible indication that I'm piloting something that requires AdBlue solution -- proof of Mercedes' mastership of diesel vehicle refinement.

On our closed test track, the ML needed only 6.9 seconds to get to 60 mph, and it reached the quarter mile in 15.3 seconds at 87.8 mph. A panic stomp on the 13-inch front rotors from 60 mph brought the ML to a standstill in 121 feet. Such figures aren't that bad for the Vance, Alabama-made sport-ute.

But above-average straight-line sprinting is only one arrow in this five-passenger's quiver. In Sport mode -- a calibration that quickens the throttle's responsiveness, adds weight to the steering wheel's normally light rotation, and stiffens the Agility Control variable rate shocks -- the ML carries its heft with the adeptness of an NFL offensive lineman. Its build feels sturdy, its feet agile, and its reactions confident -- in a word, solid.

There's a good amount of technology to praise for this surprise athleticism, namely the dual modes (Comfort and Sport), variable height Airmatic adaptive dampers ($1610), torque-vectoring 4Matic all-wheel-drive system, Active Curve Control (a $2910 special order option that uses electro-hydraulically variable stabilizer bars to reduce roll), and chic 20-inch twin 5-spoke alloys ($750). Sport mode with paddles flapping is also the only way to hold gears without an automatic upshift.

Another arrow in the Bluetec's stash: fuel economy. Engineers claim the ML will venture more than 600 miles on a single 27.7-gallon tank. We surpassed that mileage milestone multiple times without much fuss. We also frequently recorded combined averages of 25 mpg, well above the EPA's 23 mpg combined estimate (20/28 city/highway). (A gas-chugging ML350 4Matic is rated at 18/23/20 city/highway/combined.)

The $4000 jump in base price from regular $48K-plus ML to $52K-plus Bluetec affords you no more high-dollar standard amenities. You get all the same equipment, such as heated front seats, power sunroof, dual-zone climate control, power liftgate, and Bluetooth connectivity. Almond Beige Leather ($1620) and no-charge walnut wood trim spruced up the cabin. So too did the Premium 1 Package ($3700), which adds folding exterior mirrors, COMAND with navigation and rearview camera, driver's seat memory, and iPod/MP3 player interface. Some editors mentioned hampered rearward visibility in their specific seating positions, so checking the box next to the $850 Lane Tracking Package might be a good idea.

We had three major gripes with the ML's interior -- and all current models with COMAND, for that matter. First, COMAND isn't as intuitive as some competitors' multimedia interfaces. Front passengers -- people with law and master's degrees, mind you -- more often than not couldn't figure out how to change the radio frequency when they weren't already on the radio menu. Second, there's still an archaic number keypad on the dash -- who else does that nowadays? And third, if you want the rearview camera to work while reversing from a parking spot, the system must be switched on -- after a week in the ML, this was the most annoying grievance of all. Otherwise, as expected from the crew in Stuttgart, the ML's interior is a beautifully styled, well-organized, comfortable place to spend any amount of time.

In a special turn of events, our test included an off-road adventure at one of northern California's OHV parks. Lucky for us, a storm passed through the night before, leaving a muddy mess to play in. With 20-inch all-seasons and an all-wheel drive system designed primarily to improve road handling, the ML is no Baja racer. The sensors, brakes, and tires argued heatedly with their CPU masters that day. Figuring out what to do about the gooey nastiness below was almost a totally foreign decision for them to makealmost. A few editors heard and felt jolting ABS brake applications during downhill crawls with the descent control system switched on. Still, when driven judiciously, we were pleasantly surprised with the Bluetec's soft-road capabilities. It didn't get stuck, and that's what really mattered when having fun in a remote OHV park.

With this ML350, Mercedes has built a gem of a mid-size diesel SUV that's specifically -- and superbly -- refined for discerning luxury buyers who are as much attracted to miles-per-gallon marks as they are to grunt and comfort. Is the Bluetec worth the cost of entry and the slightly higher fuel prices? For a segment benchmark such as this, the answer is an emphatic "Yes."


2013 Mercedes-Benz ML350 Bluetec
BASE PRICE $52,175
PRICE AS TESTED $64,585
VEHICLE LAYOUT Front-engine, AWD, 5-pass, 4-door SUV
ENGINE 3.0L/240-hp/455-lb-ft turbodiesel DOHC 24-valve V-6
TRANSMISSION 7-speed automatic
CURB WEIGHT (F/R DIST) 5109 lb (54/46%)
WHEELBASE 114.8 in
LENGTH x WIDTH x HEIGHT 189.1 x 84.3 x 70.7 in
0-60 MPH 6.9 sec
QUARTER MILE 15.3 sec @ 87.8 mph
BRAKING, 60-0 MPH 121 ft
LATERAL ACCELERATION 0.83 g (avg)
MT FIGURE EIGHT 27.0 sec @ 0.65 g (avg)
EPA CITY/HWY FUEL ECON 20/28 mpg
ENERGY CONS., CITY/HWY 191/137 kW-hrs/100 miles
CO2 EMISSIONS 0.97 lb/mile