For years, Mercedes-Benz has fed its U.S. customers a diet of ever-more-powerful engines in its E-class sedan. It's been decades since the forebearer to today's E-class had a four-cylinder engine behind its signature radiator grille - at least in America. Our lowliest E-class Benz, which isn't so lowly at all, has instead come with a six, with a V-8 as the move-up engine, and, for a time, a supercharged V-8 in the AMG version, which has since switched to a normally aspirated big-block (6.2 liter!) V-8.
In Europe, Mercedes offers those same engines, but they're the tippy top of a much larger pyramid. Four-cylinder gasoline engines and diesels, considered insufficiently muscular to power a compact C-class over here, comprise the bulk of E-class sales over there. For 2010, the redesigned E-class has a new family of four-cylinder gasoline and diesel engines at the base of its powerplant pyramid.
The two gasoline engines are turbocharged and direct injected. Both displace 1.8 liters. The more powerful version makes 201 hp, which isn't much shy of a typical V-6's output and is enough to send the E250 CGI from 0 to 62 mph in a not too shabby 7.7 seconds. With its five-speed automatic, the E250 CGI is rated at 32 mpg (combined city/highway, European test procedures). Its lesser powered but more economical sibling is good for 181 hp and is a full second slower to 62 mph, but returns 35 mpg in the E200 CGI, which has a standard six-speed manual.
The diesels, however, are even more impressive. The three four-cylinder units are all the same size: 2.1 liters, and all three are turbocharged (naturally) and use common-rail direct injection. Output of the three engines varies much more in torque than in horsepower. The E200 CDI, with only a single-stage turbocharger, is rated at 266 lb-ft of torque. The E220 CDI upgrades to a dual-stage turbo and musters 295 lb-ft of torque. The E250 CDI pumps out a V-8-like 369 lb-ft. Interestingly, all three diesels achieve the same, 44 mpg combined fuel economy rating, with their standard six-speed manual gearbox.
Curious to see how a 44-mpg diesel E-class would meet my American expectations, I grabbed an E220 CDI for a spin during the launch of the new 2010 model. Unfortunately, it was equipped with the optional automatic, thus making it a 39-mpg diesel E-class. Still, that's a long way from the mid-20s combined fuel economy of the U.S. market's gasoline V-6.
As with so many modern diesels, the E220 CDI blows old notions of turbo-diesel driveability out of the water. The sound quality is different from a gasoline engine's, but it's really only discernable during acceleration, not when cruising or at idle. The two-stage turbo is seamlessly integrated, so throttle response is predictably linear.
I drove an automatic, which was a five-speed (with a traditional shift lever on the console) rather than the seven-speed automatic (with electronic, column-mounted PRND selector) that Mercedes puts in our V-6 and V-8-powered E-class cars. Factory-measured acceleration is a brisk 8.3 seconds from 0 to 62 mph, and indeed the diesel steps out quickly off the line, thanks to an ultra-low (1400 rpm) torque peak. Mid-range acceleration is more leisurely than with our gasoline engines, but would be plenty for most drivers. High-speed cruising, though, is effortless. The only time the E220 CDI feels slow is when you try to drive it hard through tightly curving back roads; this is not a car that wants to charge from one apex to the next.
Overall, though, this 39-mpg E-class comes across as a very convincing executive conveyance that just happens to be more economical than even the smallest econobox. Should the dark days of $4 a gallon gasoline return - and who thinks they won't? - Mercedes, with this engine, or better yet, the just as economical but even more potent 369-lb-ft E250 CDI version, could blow Americans' minds by providing hybrid-like fuel economy and a luxury-car driving experience.