2014 Mercedes-Benz GLK250 BlueTEC 4MATIC Test Drive and Review

The Diesel People's SUV

2014 Mercedes-Benz GLK250 BlueTEC 4MATIC. Photo © Jason Fogelson

Diesel passenger vehicles are common around the world, but they're still rare in the United States. We've always craved the instant horsepower of the gasoline engine, rather than the steady torque of a diesel. But technology marches on, and modern turbo diesels are quieter, more efficient, and offer more immediate performance than ever before. Mercedes-Benz has always been on the forefront of diesel. Relative price has always remained the obstacle that has kept US customers from fully embracing Mercedes-Benz diesels.

The new GLK250 BlueTEC may finally have a chance to overcome that obstacle and become the breakthrough diesel SUV. The 2014 Mercedes-Benz GLK250 BlueTEC 4MATIC comes with a base price of $38,980 ($57,405 as tested), including a 4-year/50,000-mile basic warranty and EPA fuel economy estimates of 24 mpg city/33 mpg highway. Let's drive.

First Glance

Mercedes-Benz has a wide lineup of SUVs, from the military-inspired G-Class (Gelandewagen) to the seven-passenger GL-Class to the mid-sized M-Class to the compact GLK-Class. There used to be a seven-passenger R-Class, too, and there's an upcoming GLA-Class compact SUV announced for 2015. It's the widest range of SUVs this side of Toyota's (Land Cruiser, Sequoia, 4Runner, Highlander, Venza, FJ Cruiser, RAV4), and certainly the broadest range of luxury SUVs.

GLK has been in the USA since 2010, and underwent a cosmetic makeover for 2013. For 2013, the big news was the new four-cylinder diesel engine. My 2014 model test vehicle was equipped with the diesel, which we'll discuss more later.

Mercedes has carved out a very consistent brand look across the SUV lineup, with the exception of the outlier G-Class. GL-, GLK- and M-Class vehicles share a lot of styling cues, from the prominent grille with the proud Mercedes-Benz star emblem to the clean crisp lines and tall greenhouse. GLK bears up to close inspection, with flawless paint, fit and finish. The only reliable way to differentiate GLK models is by looking at the badges. GLK240 BlueTEC doesn't splash its diesel status all over the place; just where it counts.

In the Driver's Seat

I appreciate a design meme when I encounter a new dashboard, and GLK's got one: round with chrome trim. Everywhere that the M-B designers could repeat the meme in the GLK cabin, they did so, with nice results. I especially appreciate the way that form follows function with some of the best HVAC vents ever, the four round, versatile units mounted in the GLK's dash. They make controlling and directing the airflow in the front cabin a precise art, a delight for the comfort-oriented.

Putting the GLK into gear doesn't require removing your hands from the steering wheel, as a steering column-mounted controller snicks the transmission from Park to Drive. Keeping the controller up there has the additional benefit of freeing up space in the center console, a welcome feature in an SUV.

My test vehicle was equipped with the $2,860 Multimedia Package of options, which included a 7" display (properly inset into the top of the center stack), M-B's COMAND system with navigation, a rearview camera and more -- all essential equipment for a luxury SUV. Additional options on my test vehicle included full leather seating ($1,850) and the Premium Package ($3,450), which covers a few major options like the Panorama Sunroof and Power Liftgate. Seems like the base GLK250 doesn't come with too many of the features that I'd consider baseline for "luxury." Options add up quickly, as evidenced by the $18,000-plus worth of extras on my test vehicle.

GLK's second row is roomy enough for two adults and a child, befitting the vehicle's size and stature. Headroom is good, and outward visibility from all seats is superb. Behind the second row, there's 23.3 cubic feet of luggage space. Flop the second row flat (easily done), and 54.7 cubic feet of load space is free for junk.

On the Road and Off

Finally, we get to the powertrain. I often test out diesel vehicles on my passengers without ever revealing the fuel type. After they've been riding around with me for a while, I ask them for their impressions of the vehicle. I don't ask any leading questions, just "What do you think?" With the GLK250, not a single passenger guessed that it was a diesel, and all expressed surprise when I revealed it. As a driver, I quickly became enamored of the 2.1-liter inline-four cylinder twin-turbo diesel engine and its 200 hp and 369 lb-ft of torque. It gets hooked up to the same seven-speed automatic transmission and 4MATIC all-wheel drive system that graces the GLK350 gasoline model (302 hp/273 lb-ft of torque from a 3.5-liter V6). The gas version is faster, no doubt. It is capable of scooting from 0 - 60 mph in 6.4 seconds, while the diesel takes 7.9 seconds to achieve the same velocity. But the gas GLK gulps down fuel at the rate of 19 mpg city/24 mpg highway, while the super-efficient diesel rates at 24 mpg city/33 mpg highway, a significant improvement.

Part of the reason that the diesel is slower is because of the way that diesel engines deliver power; part of the reason is that the diesel GLK is about 250 lbs heavier than that gas version. I didn't get a chance to drive the two versions back-to-back, which I would highly recommend to any buyer who's considering a GLK. My impression of the diesel GLK was that it was very well-sorted on the road, with very good balance, steering and handling characteristics for an SUV, and a nice quiet ride in most everyday conditions.

Journey's End

The difficulty of comparing apples to oranges has been wiped away in the GLK. No longer do you have to decide between "saving money" with a very expensive diesel variant or getting good real world performance. The inconvenience factor of diesel is minor, especially with the help of a smartphone or Mercedes-Benz's telematics system. GLK250 has a 7.9-gallon AdBlue tank. AdBlue is an aqueous urea solution also referred to as "Diesel Exhaust Fluid" or "DEF." The tank needs to be replenished about once a year or every 10,000 miles (GLK notifies you via the driver information center on the dash) -- no big deal. The difference in performance between the gas and diesel GLK variants is a matter of driving style and taste. If you're a conservative driver, you might not ever notice the 1.5-second differential. If you're a hot rod, you'll probably be disappointed in the gas version anyway.

GLK250 BlueTEC's most direct competition is probably the Audi Q5 TDI, the only other diesel compact luxury SUV. Other compact luxury SUVs to consider include the Acura RDX, BMW X3, Infiniti QX30, Lexus RX and Cadillac SRX.

Really, though, if you're considering a GLK, you're probably deciding between the gas or diesel models. Part of the decision has to be based on current market conditions, where diesel fuel is slightly more expensive than the premium unleaded gasoline that GLK350 requires, thus offsetting some of the savings you could expect from improved fuel economy. Part has to be based on your guess about the future of fuel prices -- I can't help you there, except to reaffirm my belief that fuel prices will continue to rise for the foreseeable future. The higher prices get, the more important efficiency becomes. GLK250 represents diesel without significant sacrifice, which sounds like a backhanded compliment, but is actually high praise.

The GLK250 BlueTEC 4MATIC actually has a base price that is $500 lower than the GLK350 4MATIC's base price, so the decision comes down to: Gas or diesel?

Disclosure: Review samples were provided by the manufacturer. For more information, please see our .