[dropcap]T[/dropcap]he E250 BlueTEC sedan was introduced in 2014 as the newest model in the Mercedes-Benz E-Class. I finally got the chance to test drive a 2015 copy of this marvelous example of automotive technology.
Little has changed from last year, but the styling remains sleek, smart and stylish, and with a new turbodiesel engine it delivers an impressive 45 miles per gallon on the highway and 28 mpg around town.
The E250 BlueTEC sedan is the first diesel E-Class to be available with 4MATIC and achieves best-in-class fuel efficiency for a midsize luxury sedan, and for the entire industry in the same size range. When equipped with optional 4MATIC all-wheel drive, fuel mileage numbers are still impressive at 42 mpg highway and 27 in the city.
Under the hood
The high-efficiency, all-aluminum, inline four-cylinder turbodiesel engine uses four valves per cylinder and dual overhead camshafts with vane-type variable valve timing to producing 195 hp and 369 pound feet of torque.
To smooth out the vibration of an in-line four-cylinder engine, two Lanchester balance shafts spin at twice crankshaft speed in low-friction roller bearings. During normal operation, the advantage of the twostage turbocharged system is evident as there is no turbo lag, a very fast throttle response, a broad torque curve across the entire engine speed range and improved performance.
Fuel pressure for the BlueTEC direct fuel injection system is 2,000 or 28,400 pounds per square inch, which delivers more power and lower exhaust emissions. Higher ignition fuel pressure means the four piezo injectors can be adjusted even more precisely as engine load and speed change.
To ensure the E250 BlueTEC meets exhaust emission regulations in all 50 U.S. states, the BlueTEC system uses AdBlue injection to make the diesel as clean as a stateof- the-art gasoline engine. Newly accessibly through the fuel filler door, the water-based AdBlue urea solution is carried in a small tank and metered into the exhaust in minute quantities, so the tank needs refilling only during routine scheduled maintenance.
When AdBlue is injected into pre-cleaned exhaust gas, ammonia (NH3) is released, converting nitrogen oxides into harmless nitrogen and water in a downstream catalytic converter. Called SCR, for selective catalytic reduction, this process creates the most effective method of exhaust gas aftertreatment currently available.
Optional on the E250 BlueTEC, the latest Mercedes-Benz 4MATIC system is cleanly integrated into the seven-speed automatic transmission, so it fits neatly into the standard body and utilizes the existing front suspension. Fuel efficiency has been improved by several innovations that minimize the energy needed to turn the extra gears and shafts. Full-time four-wheel drive provides year-round traction and stability benefits on both wet and dry roads.
The MRSP on the Mercedes Benz E250 BlueTEC is $51,400.
[author image=”http://www.samaonline.org/Ron.jpg” ]Ron Beasley is the automotive editor for Miami’s Community Newspapers. He may be contacted by calling 305-662-2277, ext. 261, or by addressing email correspondence to LetsTalkCars@aol.com.[/author]