Drive of sufficient length through the lush green environs around and inPortland and Oregon, and you’re guaranteed to encounter greater than a few big rigs hauling impossibly huge stacks of cigar-shaped logs in giant steel humidor cages and spewing tell-tale clouds of thick black diesel particulate matter. When you pass one in a cutting-edge clean-diesel car like the 2014 Mercedes-Benz E250 Bluetec sedan, it works as a stark reminder of how far diesel-powered passenger cars have come, and how far diesel must go to stay relevant in ait has become ubiquitous for massive long run trucks – is the mileage/range advantage over gas-powered engines. In Europe, where stratospheric fuel prices are already the norm for years, diesels have become a major segment of the market. For example, Mercedes offers many diesel-powered choices for the newly updated 2014 E-Class in thethe alternatives are much more limited. However the Europeans have been carefully re-establishing a diesel beachhead, and Benz has been on that front line. The 2014 E250 Bluetec is the latest U.S.-market E-Class to be made available from Mercedes in the current passenger-car diesel era, and never surprisingly, the automaker says it’s more efficientfrom the GLK250 crossover), which replaces the 3.0L six that generated 210hp and 400 lb-ft of torque that propelled the outgoing E350 Bluetec. Without quite as powerful as the six at 195hp and 369 lb-ft (peak torque is available from 1600-1800rpm), Benz officials insist the 2.1L will perform at least as well as the 7.5sec -60mph and also the 15.6sec quarter-mile a 2011 E350 Bluetec sister publication Motor Trend tested achieved way back in 2010. A GLK Motor Trend just tested using the same engine as being the E250 hit 60mph in 7sec flat and 15.3sec within the quarter. We expect similar numbers from the E-Class diesel. Benz also added two balance shafts to the engine to help minimize the vibration characteristic of in-line fours in order to deliver the sort of smooth power delivery E-Class buyers cameHow do the E250 achieve the same acceleration with less overall power? Mainly thanks to a twin-turbo setup that utilizes a small high-pressure turbo mounted at the exhaust manifold in order to deliver higher boost at lower engine revs. In order to smooth out overall throttle delivery, a larger, low-pressure turbo is mounted further downstream. Mercedes says the setup reduces turbo lag and helps broaden the torque curve across the rev range. Based on Benz accomplishes the neat trick of delivering more power and minimize exhaust emissions at the same time, fuel pressure for the 2.1L’s direct fuel injection method is rated at 28400 lb per square in ., which. Benz says the system’s high-pressure setup permits the engine’s four piezo injectors being adjusted even more precisely as engine load and speedinto the exhaust to help keep particulate matter in check and the E250 as clean just like any E-Class from an emissions standpoint. AdBlue is refilled at 10000 mile intervals as part of the overall maintenance process.