Instrumented Test
TESTED
The idea of a four-cylinder diesel in a Mercedes E-class sedan might seem a little heretical to dedicated aficionados of the Benz chronicles. If you ignore the GLK250 BlueTec introduced for 2013, Mercedes hasn’t offered a four-cylinder diesel in the U.S. since the 1985 190D. And that car was the predecessor of the smaller C-class, whereas the E is a mid-sizer accustomed to propulsion supplied by sixes. The previous E-class BlueTec used a 3.0-liter V-6 turbo-diesel that offered up smooth, quiet operation and a torrent of 400 lb-ft of torque.
Will the new Mercedes compression-ignition four assuage doubters? The 2.1-liter huffs up 195 horsepower but, more important, 369 lb-ft of torque, which is nicely exploited by the seven-speed automatic transmission. And thanks to common-rail diesel technology, it’s a far more civilized power source than the clattery smokers of the 190D era.
Sneaky Fast
Torque is one of the main turbo-diesel virtues, but it’s important to remember what it contributes to performance—and what it doesn’t. Low-end grunt is a plus for getting a hefty (4365 pounds, in this case) car out of the starting blocks and across the intersection in a hurry, and the E250 accomplishes this task well.
But as speeds rise, torque gives way to horsepower, and like all turbo-diesels, the E250’s 2.1-liter doesn’t make a lot of it compared with gasoline engines. With 195 horsepower on tap, acceleration tends to be leisurely, with 0 to 60 taking 7.8 seconds and the quarter-mile arriving in 16.1 at 86 mph. However, once the E is rolling, the action of the sequential twin turbochargers summons up plenty of speed, and because the car is quiet, it’s easy—too easy, really—to look down and find you’re motoring blissfully along at a pace that exceeds most posted speed limits. Be warned.
Although the E250 isn’t exactly a sports sedan, it comports itself well at high speeds. Body motions are nicely controlled, and responses to orders from the helm are prompt, whether you’re bending the Benz into a fast sweeper or rapid transients. The electric power steering is reasonably quick and more accurate than many similar systems, and the paddle shifters lend a sporty element. And whereas there’s enough roll stiffness in the suspension to limit body lean in corners, ride quality won’t make owners unhappy. Let’s call it Euro firm, but all-day comfortable—although really sharp bumps can use up all the suspension travel.
Of course, the E250 BlueTec isn’t the only mid-luxury German sedan in the compression-ignition game. For a few thousand dollars more, Audi (in the A6/A7 TDI) and BMW (535d) offer 3.0-liter six-cylinder turbo-diesels with considerably more power and torque, as well as acceleration that slices more than two seconds off the E250’s measured 0-to-60 sprint. It really boils down to the car’s personality, whether you prefer the Audi’s designer/tech vibe, BMW’s sportiness, or the Merc’s luxo-cushy stress relief.
Starting with a base price of $54,825 (including 4MATIC all-wheel drive, a wise addition for Snowbelters), our E250 BlueTec sedan added Lunar Blue paint ($720), split-folding rear seats ($440), a rear deck spoiler ($300), the $3870 Premium 1 package (COMAND with navigation, voice control, Harman/Kardon surround sound, satellite radio, heated front seats, rear camera, and power rear sunshade), the $1290 Parking Assist package, and the $2800 Driver Assist package (various electronic nannies, including Distronic Plus with steering assist, active blind-spot monitor, active lane-keeping assist, cross-traffic monitor, and Pre-Safe braking with pedestrian protection).
The MPG Incentive
The primary diesel virtue, obviously, is fuel economy. EPA estimates for the E250 are 24 mpg city and 38 highway compared with 22/33 for the E350 and its premium-unleaded-fueled V-6. We logged 30 mpg, even though our test involved quite a bit of vigorous driving. In ordinary use, we’d expect even better results, and at a steady 70-mph cruise with the little diesel humming along at 1700 rpm, one could easily traverse Nebraska and have enough fuel left for most of Iowa or Wyoming, depending on your heading. Bathroom breaks are your call.
