Plentiful torque is nice, but exemplary fuel economy may be the GLK250’s greater virtue.

Most automakers’ representatives will then present a sad but salient argument against diesel in the US. Not Mercedes-Benz. The company has a long and unbroken history of diesel power – the longest, in fact: Its 1936 260D was the world’s first diesel-powered passenger car, and the first in a line that stretches to this one: the new GLK250 BlueTEC, the first diesel in the compact-SUV segment of the market, one that includes the Audi Q5 and the BMW X3.

A thorough freshening for 2013 gave the GLK more style and substance, with smartly revised front-end styling, an upgraded interior and, in the gasoline V6-powered GLK350, more power and improved fuel economy. Mercedes considers its smallest SUV to be a gateway to the brand, a first three-pointed star for buyers who, with careful cultivation, may become regulars. As such, it is a model that gets a lot of attention The GLK250 BlueTEC is a late-year addition to the range.

Providing the motivation in this newest GLK is a 2.1-litre, 4-cylinder diesel engine, matched to Mercedes’ excellent seven-speed automatic transmission and 4Matic all-wheel drive (there is no rear-wheel-drive GLK250). With twin turbochargers and direct fuel injection, the engine delivers 200 horsepower and 369 foot-pounds of torque. The turbos are sequential – a small, high-pressure turbine that spools up quickly and a larger one that comes on later and provides the bulk of the oomph. The result is seamless power delivery, with minimal turbo lag. A testament to its versatility, this 2.1-litre diesel, which debuted in Europe back in 2009, is set to power Mercedes' rear- and all-wheel-drive E-Class models for 2014, as well as the company's full-size Sprinter van.

Price-wise, the GLK250 BlueTEC starts at $39,495 (inclusive of the $905 destination charge), placing it neatly between the rear-wheel-drive GLK350 ($37,995) and the all-wheel-drive GLK350 4Matic ($39,995). That said, like all Mercedes-Benzes (and all vehicles from premium German automakers, for that matter), that price is bound to escalate. A Mercedes spokesman noted that the average transaction price for a GLK is $43,000, but the tested vehicle, loaded to the gills with all manner of optional safety, comfort, convenience and style features, ballooned to an eye-widening $57,635.

And yet, the GLK’s fiscal liberty is forgiven (or at least momentarily forgotten) with a stab of the throttle. On the road — on any road, truth told — the GLK250 BlueTEC is a winner. Over smooth asphalt, the SUV reveals its sporty C-Class origins with predictable body motions and admirable grip in the curves, and on rougher patches – and even off the pavement entirely – it is never less than fully composed, thanks to a stout structure and generous wheel travel. The GLK350’s V6 is a model of decorum, but the GLK250’s diesel four is hardly unrefined. The engine manages to conceal its cylinder count during all but the most full-on acceleration. And the monumental rush of torque, which peaks at a very low 1600 rpm, is thoroughly satisfying.

Plentiful torque is nice, but exemplary fuel economy may be the GLK250’s greater virtue. Even with standard all-wheel drive, the SUV returns an admirable 24mpg in the city and 33mpg on the Interstate, handily topping the GLK350 4Matic’s 19mpg city and 24mpg highway – figures, it should be noted, that are achieved on pricier premium fuel. Like the six-cylinder diesel engine in Mercedes’ M- and GL-Class SUVs, this engine receives minute injections of AdBlue, a water-based urea solution that mitigates noxious emissions, ensuring that the diesel GLK is meets the same standards of cleanliness as its gasoline-powered sibling, even in California, whose California Air Resources Board has crafted some of the nation’s toughest emissions regulations. The solution is contained in a small on-board reservoir, which is refilled at regular service intervals, says Mercedes.

Refined and easy to live with, the GLK250 joins a growing field of diesel-powered passenger vehicles, from the $24,290 Volkswagen Beetle TDI to the $93,905 Mercedes-Benz S350 BlueTEC. These modern diesel-powered vehicles are neither noisy nor smelly, and thanks to the ever-improving availability of ultra-low-sulfur diesel fuel in the US, drivers are no longer forced to fill up alongside the big rigs at highway truck stops. And that, unless you have a yen for a greasy burger and a free shower, is very good indeed.

The 2013 GLK250 BlueTEC is landing in North American Mercedes-Benz dealerships now.

Vital stats: 2013 Mercedes-Benz GLK250 BlueTEC 4Matic