In the tense days of this nation鈥檚 twin gas crises in the 1970s, one automaker dominated U.S. Since then, that number has shrunk to a modest 6%. Yet the diesel engine has come a long way since the soot-stained versions from 30 years ago. Although many still have a distinctive idle not unlike your kid鈥檚 school bus, they are unquestionably cleaner, quieter, and more efficient. Mercedes is now looking to boost interest by making these oil-burning engines more affordable. It鈥檚 in the process of bringing to the U.S. The first of its vehicles to get this power plant is the 2013 GLK250 BlueTec, Mercedes鈥?compact crossover SUV. Highway 1 recently spent a day testing one on the freeways and scenic back roads of Malibu to get a sense of this motor鈥檚 viability. After 80 miles of testing, it鈥檚 clear that if you鈥檝e had your eye on the GLK, the diesel model is the one to choose. The evidence is in the numbers.

In the tense days of this nation鈥檚 twin gas crises in the 1970s, one automaker dominated U.S. Since then, that number has shrunk to a modest 6%. Yet the diesel engine has come a long way since the soot-stained versions from 30 years ago. Although many still have a distinctive idle not unlike your kid鈥檚 school bus, they are unquestionably cleaner, quieter, and more efficient. Mercedes is now looking to boost interest by making these oil-burning engines more affordable. It鈥檚 in the process of bringing to the U.S. The first of its vehicles to get this power plant is the 2013 GLK250 BlueTec, Mercedes鈥?compact crossover SUV. Highway 1 recently spent a day testing one on the freeways and scenic back roads of Malibu to get a sense of this motor鈥檚 viability. After 80 miles of testing, it鈥檚 clear that if you鈥檝e had your eye on the GLK, the diesel model is the one to choose. The evidence is in the numbers.

500 less than its AWD gas counterpart, the GLK350. Yet the BlueTec gives you 33% better combined fuel economy despite weighing about 250 pounds more. The GLK250 is rated at 24 mpg in city driving and 33 mpg on the highway. Mercedes says drivers can go up to 515 miles on a single tank of gas; enough to drive from Los Angeles to Tucson with a smidge left over. In our day testing the model in mixed driving, we averaged a healthy 27 mpg. What鈥檚 encouraging about those numbers is the BlueTec never felt underpowered. Yes, its 200-horsepower rating is 102 less than the V-6 in the GLK350. And the diesel is a second and a half slower from zero to 60 mph. But the BlueTec benefits from that tasty side effect of diesel engines: torque. It has a stout 369 pound-feet, nearly 100 more than the V-6. These numbers are courtesy of the GLK250鈥檚 2.1-liter, twin-turbocharged inline four-cylinder diesel engine. It鈥檚 the same engine that Mercedes will introduce this fall in the recently refreshed E-Class sedan. Like the GLK orientation, the E250 BlueTec will be the lowest priced version of the E-Class available. This engine is a smooth-running delight. 57,635), you鈥檇 be hard pressed to know what was under the hood was anything other than the gas engines us 鈥楳ericans are so used to driving. The rest of the diesel driving experience was near identical to that of the V-6 powered GLK. The BlueTec model comes with the same seven-speed automatic transmission that matches its engine for silky performance. Though no sports car, the GLK handles its mass as well as any of its buyers need it to. The vehicle鈥檚 dimensions don鈥檛 change at all, so you鈥檙e still riding in a tidy but practical package.

That, of course, is no surprise; Mercedes-Benz has always known a thing or two about diesels. Now, North America is finally catching up to the rest of the world. The GLK continues to be available with a V6 (we鈥檒l come back to that), but it can also be equipped with a diesel engine, like its big brother, the GL. Since 80% of GL units sold in Canada come with the diesel engine (GL 350 Bluetec), it鈥檚 safe to bet that the GLK diesel will be just as popular. The diesel engine found in the GLK 250 is a 2.1-litre (2.143 cc) four-cylinder twin turbo. Don鈥檛 waste your time trying to find the link between the engine capacity and the vehicle name. At Mercedes, confusion reigns. In any case, it develops 200 horsepower at 3,800 rpm, which isn鈥檛 much, but it redeems itself with a torque of 369 lbs-ft at 1,600 rpm. This mill is paired with the 7G-Tronic Plus automatic transmission that activates the 4Matic all-wheel drive.

While Mercedes-Benz usally slaps the 鈥? Matic鈥?label on all cars equipped with this efficient drive train, the GLK 250 doesn鈥檛 mention it at all on its body. However, the word BlueTEC is emblazoned on the liftgate, which surely makes up for it in the eyes of owners. Mercedes-Benz calls its diesels 鈥淏lueTEC,鈥?which is reminiscent of another name: AdBlue. This urea-based liquid helps the motor run extremely clean. You fill it up while you鈥檙e changing your oil, making the operation more expensive. The GLK 250 is a relatively heavy vehicle (1,925 kg), so don鈥檛 expect to win any drag races. As with most Mercedes-Benz products, the accelerator isn鈥檛 terribly progressive and it鈥檒l take some time to get used to, which may have distorted our impressions considering that we only drove it for half a day. Mercedes claims that it can charge from 0-100 km/hr in eight seconds flat. The GLK 250 really excels when it comes to fuel consumption and the noble manufacturer is announcing a combined 7.2 L/100 km.

In reality, that doesn鈥檛 mean much. During our test drive, we recorded an excellent average of 7.0 L/100 km, and I imagine that an average fuel consumption of 8.0 L/100 km is realistic. For those who get a nosebleed every time you hear the word 鈥渄iesel,鈥?let me reassure you. From the inside of the GLK, you almost have to know in advance that there鈥檚 a diesel engine lying in front of you. The typical diesel engine noise is a little more audible from the outside, but we鈥檝e come a long way from the rattling, smelly engines of the old days. There GLK can also be outfitted with a 3.5-litre V6 that finally includes direct injection. Thanks to its 302 horsepower and its 273 lbs-ft of torque available between 3,500 and 5,250 rpm, this V6 moves the GLK smoothly and swiftly. Its sound is more pleasant than that of the diesel and it goes from 0-100 km/hr 1.5 seconds faster, according to Mercedes. However, it consumes 2.5 more litres per 100 km (9.7) combined.