Among enthusiasts, there's a saying regarding project cars that goes something like this: "Cheap, fast, reliable -- pick two." The same idea could apply to luxury SUVs, only the descriptors could be changed to "powerful," "capable," "affordable," and "efficient." Building a vehicle that possesses all of those qualities isn't easy, but one of the best ways to satisfy the power and efficiency requirements is to offer a diesel option, as Mercedes-Benz does with every SUV it sells. We got our hands on a 2014 Mercedes ML350 Bluetec to see if it could check a few more boxes.

The keys to the ML350 Bluetec landed in my lap just in time for a day trip to San Diego. The SUV's indicated 575-mile range on a full tank of diesel meant I could get there and back with no stops, and still have enough to putter around the rest of the weekend. The ride was glass-smooth the entire way, and even the heavy rain I encountered later in the drive didn't slow the M-Class down much, thanks to the 4Matic all-wheel drive system, which comes standard on the Bluetec. That day, the ML's rain-sensing wipers were another welcome feature.

After the road dried a bit, I made the most of the ML Bluetec's all-aluminum 3.0-liter turbodiesel V-6, which provides 240 hp and an ample 455 lb-ft of torque. That twisting force surges around the 1800-rpm mark, pushing you back in your seat as the relatively low revs climb. My only problem was that I couldn't summon this earth-moving torque on command at highway speed. After a lane change, I would stomp on the accelerator to pass (and to feel that corrupting rush of torque again) and it would take a moment for the seven-speed automatic transmission to shift down to an appropriate gear. Getting back into the engine's sweet spot required two or sometimes three downshifts, which I usually chose to initiate manually using the steering column-mounted paddle shifters instead of waiting for the transmission to figure out what I wanted. It's not terrible, but I think the diesel's gearbox could use a recalibration for the next refresh to make highway changes more immediate.

When the M-Class diesel gets going though, it really goes. Test results were nearly identical in every measure to the 2013 ML350 Bluetec we tested, which is to say it's still quick for an SUV. Accelerating from 0-60 mph required 7.0 seconds, and completing the quarter mile took 15.4 seconds. That's par for the course when compared with other diesel SUVs, such as the Volkswagen Touareg TDI, Porsche Cayenne diesel, and Jeep Grand Cherokee EcoDiesel featured in our last comparison test. In that test, the ML placed third while the Jeep took the win. Though the ML Bluetec couldn't topple its competitors in that test, compared to its gasoline-fed counterpart it's easily the better buy. The standard ML350, which produces 302 hp and 273 lb-ft from a naturally aspirated 3.5-liter V-6, is estimated by Mercedes to hit 60 mph in 7.3 seconds. But the diesel's 182-lb-ft advantage, which you'll notice almost immediately in the lower revs, is well worth the minimal premium over an ML350 4Matic.

Also worth the extra cash is the Bluetec's 20/28 mpg city/highway EPA-rated fuel economy, up 3 mpg in the city and 6 mpg on the highway compared to the gas-powered ML350 4Matic, and up 2 mpg and 4 mpg compared to the two-wheel-drive ML350. During my weekend with the Bluetec, indicated average fuel economy held steady at 24 mpg -- and that was with me pushing the loud pedal to the floor at every opportunity.

As far as amenities, our tester was nice enough, but a bit light on content for a $60,000-plus Mercedes. Hands-free keyless entry and push-button start were missing, as they’re a $650 option. At this level, that feature should be standard equipment, as it is on many non-luxury vehicles from Korea and Japan. What does come standard is a power liftgate, which is nice. That button-operated opening provided easy access to the spacious 38.2-cu-ft cargo area. A total of 80.3 cu-ft of cargo volume is available once the second row of leather seats is folded down. Heated front seats come standard, and were much appreciated on the rare cold, wet nights in Southern California. Our car also had the $3920 Premium 1 package, which added a hard drive-based navigation system and rearview camera to the COMAND infotainment system's 7-inch screen. COMAND isn't the most intuitive system in the business, but I was able to get used to its sometimes-awkward menus and not-sensitive-enough control knob in a couple of days.

Unless you really want to save a couple thousand dollars, or are for some reason married to the concept of gasoline, I see no reason to get the non-diesel ML350 4Matic. Few vehicles can successfully blend luxury, power, capability, and fuel economy well, and the ML350 Bluetec can count itself among those uncommon "have your cake and eat it too" propositions. But it still won't come cheap.


2014 Mercedes-Benz ML350 Bluetec
BASE PRICE $52,715
PRICE AS TESTED $63,700*
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) 5182 lb (53/47%)
WHEELBASE 114.8 in
LENGTH x WIDTH x HEIGHT 189.1 x 84.3 x 70.7 in
0-60 MPH 7.0 sec
QUARTER MILE 15.4 sec @ 88.0 mph
BRAKING, 60-0 MPH 120 ft
LATERAL ACCELERATION 0.83 g (avg)
MT FIGURE EIGHT 27.3 sec @ 0.66 g (avg)
EPA CITY/HWY/COMB FUEL ECON 20/28/ mpg
ENERGY CONS., CITY/HWY 189/135 kW-hrs/100 miles
CO2 EMISSIONS 0.97 lb/mile
*MT Estimated