If the exterior of the 2015 Mercedes-Benz ML250 pictured here looks nearly identical to the 2014 ML350 it replaces, that’s probably because it is. Comprehensively overhauled for the 2013 model year, the ML’s styling will get updated for next year—when it also adopts the GLE-class nomenclature—but for now the minor change in diesel ML badging is all that’s new outside; it acknowledges the arrival of Benz’s 2.1-liter dual-turbo diesel four under the hood. The same basic diesel engine that provides the Mercedes-Benz E250 sedan and GLK250 crossover with surprising punch and refinement, the 2.1-liter unit is the first four-cylinder oil-burner in decades to find its way into U.S.-market Mercedes passenger vehicles.
Comparisons are inevitable, so let’s get this out of the way right now: Packing 200 horsepower and 369 lb-ft of torque, the diesel in ML250 trim can’t match the 240-hp and 455-lb-ft ratings of the departed ML350’s turbo-diesel V-6. But losing two cylinders has its benefits, namely a reduction in weight. Registering a still-hefty 5041 pounds on the C/D scales, the ML250 nevertheless shaves 162 pounds off the 5203-pound figure of a 2013 ML350 BlueTec 4MATIC we tested for a recent diesel-SUV comparo.
Unfortunately, the reduction in weight isn’t enough to offset the loss of muscle. At 8.3 seconds to 60 mph and 16.3 seconds to the quarter-mile mark, the ML250 gives up about a second to the 7.0- and 15.4-second times delivered by the old ML350’s V-6. The torquey four-cylinder provides smart off-the-line acceleration, however, and the sequential turbochargers—a small one provides low-end boost to mitigate lag before handing off to a larger unit at higher engine speeds—do their best to keep momentum building as the seven-speed automatic imperceptibly shuffles though the gears. It’s a reasonable assumption that the suburbanites who make up the target demographic of the ML will never miss the V-6.
EPA city/highway ratings of 22/29 mpg put the ML250 right in the ballpark with competitors such as the BMW X5 xDrive35d diesel, the Jeep Grand Cherokee EcoDiesel 4×4, and the Volkswagen Touareg TDI. In our hands, the ML250 recorded 24 mpg in combined driving, an identical number to the one we measured with the ML350 V-6; we were hoping for at least a modest improvement in efficiency, given the subtraction of two cylinders and 162 pounds. What the numbers can’t communicate, however, is the 2.1-liter diesel’s willing and amicable nature. Smooth and quiet at idle (for a diesel), it has a polished quality that makes the four-cylinder compression-ignition unit in our long-term BMW 328d xDrive Sports Wagon sound a bit loutish in comparison.
Read More Via: Car and Driver