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2006 Mercedes-Benz E320 CDI

Stereotype Slayer

    We Americans like our stereotypes. For instance, everyone knows the English have bad teeth, the Chinese are short and the French are cheese-eating cowards (OK, that one may be true). Likewise, nobody argues with the American perception that diesel cars clatter like a junior high band, are slower than a chess tournament and smoke like the Marlboro Man. Except Mercedes-Benz, who has been changing consumers’ opinions one test drive at a time since the E320 CDI debuted as a 2005 model.
     After languishing at the bottom of most consumers’ priority lists for more than a decade, fuel economy is once again a factor in most automotive purchases. The past few years have seen automakers scramble for ways to improve the efficiency of their offerings with some turning to expensive hybrid technology while others reengineer their engines to automatically shut down unneeded cylinders. Of course, both of these approaches increase mpg ratings, but they add complexity, their reliability is unknown and you’ll pay a premium for them. All the while, Mercedes has been perfecting the diesel engine, and after emission regulations could be met, decided to reintroduce Americans to a diesel-powered car—and a luxury one, at that. Well we’ve met, and years of skepticism were vanquished in the first mile. The modern diesel is good. Very good.
     Our evaluation started when we twisted the key for the first time. With ears acutely tuned for the diesel clatter that would surely follow, we were prepared to call the first strike against Stuttgart’s oil-burner. But the E320 fired instantly with minimal noise disturbing the quiet cabin, thanks to Mercedes-grade sound deadening. We won’t lie; at idle after a cold start you can tell the hood isn’t hiding a gas engine, but that noise, minimal as it is, subsides quickly as things warm up. What really blew us away was how “undiesel-like” this car feels once it’s moving. At any rpm above idle the telltale diesel noise is almost nonexistent. In fact, the thing sounds like a low-revving naturally aspirated V6 instead of a turbocharged diesel. On this merit alone the engine is perfectly acceptable in a luxury car.
     Of course, the 3.2-liter 24-valve inline-six cylinder has plenty of technology to ensure it’s worthy of luxury car duty. A variable geometry turbocharger constantly adjusts its guide vanes for optimal boost and a water-cooled intercooler lowers the intake air by 180 degrees Fahrenheit.
     But the engine’s redeeming grace is the Common-rail Direct Injection (CDI) electronic fuel-injection system that allows this engine to even exist in a world of ever-stricter emissions regulations. Reading through the system’s technical details is enough to make a powertrain engineer go weak in the knees, but try to comprehend this: CDI delivers fuel to each of six electro-magnetic solenoid valves at pressures near 23,000 psi! The level of control Mercedes engineers were able to achieve with the CDI system means fuel can be precisely metered into the combustion chamber for maximum power while minimizing all the nasty byproducts of diesel combustion, including the noise.
     The cast-iron engine is rated at 201 hp @ 4,200 rpm but because of the massive torque available from just 1,800 rpm you’d never guess the horsepower was that low. The 5-speed Touch Shift does a superb job making sure all 369 lb-ft of torque, available from 1,800-2,600 rpm, is utilized. We especially liked choosing our own gears with this gearbox. A quick tap left calls up a downshift but if you hold it for just a second longer the computer will deliver the lowest possible gear for your speed. This makes passing a breeze, and when you’re done simply hold the lever to the right to re-enter standard Drive mode. A button next to the shifter switches between comfort and sport modes, but we were satisfied with comfort so in the name of fuel-economy we stayed in it most often.
     As you’d imagine with 369 lb-ft of torque ready to go just off idle, the E320 delivers V8 levels of performance. Mercedes claims a 6.6-second run to 60 mph and we believe it. You know that notion that diesels are slow? The E320 begs to differ.
     The superb Mercedes ride quality is present and accounted for thanks to the 4-link coil spring front and 5-link aluminum rear suspension with antiroll bar all borrowed in part from the last-gen S-Class. Even without Mercedes’ Airmatic suspension the car stayed commendably flat in curves and never wallowed. Passengers were impressed, and so were we.
     We were a bit surprised at how heavy the steering gets at speed, but we’re not complaining. Actually, the weighty steering bolstered that rock-solid bank vault feel that old Benzs are known for. There’s no wandering in this car. It just tracks straight as an arrow with very few corrections needed.
     The electro-hydraulic brakes can be a smidge grabby, but the brake pedal has some weight to it and Mercedes includes all the latest enhancements like four-channel ABS, Brake Assist and Electronic Brake Distribution. The front discs are 0.8-inch smaller than the rest of the E-Class lineup and for some reason the rear discs are solid instead of the vented units found on other Es. The CDI weighs even more than the V8-powered E-Class so it doesn’t make much sense to fit even smaller brakes.
     The E320’s design continues to look good (though it receives a facelift this fall), but everyone agreed the car needs a nicely finished exhaust tip (or two) since the current setup shows nothing and looks pretty wimpy. The small and unimaginative 16″ wheels also came up for criticism considering every other luxury car on the market starts with at least 17″ rims.
     About three days into our seven-day loan we had an epiphany; around this wonderful drivetrain, whose praises we had been singing nonstop, was a luxury sedan that deserved some praise of its own. Let’s start by announcing that Audi, whose interiors are considered by many as industry leading, has nothing on this car. Everywhere we looked we found beautiful materials, quality finishes and thoughtful touches. The doors in particular are finished in leather and rich-looking wood trim. The gauges are simple and legible (although we’re not a fan of the analog clock) and we love the “After Start” feature in the on-board computer, which resets and keeps track of vital information, such as average mpg and trip time, every time the car is started. The seats are firm but supportive and heated for cold mornings.
     As part of the $2,950 Premium Package our car featured a navigation system, but it’s not touch screen so it feels a generation behind the best in the industry. Also part of the package is a strong harman/kardon sound system coupled to a 6-disc CD-changer that is hidden behind a row of buttons on the center console. When you press the secret button it motors up and out of the way for access to the changer. You’ll impress passengers every time. Everyone thought the sliding wood lid on the center console was beautiful, but some thought a well-padded leather lid in its place would be more comfortable. Climate controls are straightforward and the folding rear headrests were a great compromise between passenger comfort and visibility when you’re the only one onboard.
     We know the EPA’s miles per gallon rating of 27 city and 37 highway isn’t pie-in-the-sky high like a hybrid’s because we consistently returned 34-35 mpg in a variety of trips. That’s most impressive because the gains in power and efficiency now come without the traditional diesel downfalls.
     Besides the Premium Package, which is a great value, the only other extra cost item was $690 for pewter paint. That means $55,465 buys you an incredible luxury car with a big trunk and a class-leading interior that will return 35 mpg all day long. On top of that comes the reliability inherent in a well-built diesel. In fact, Mercedes set several world records while running the European version of this car for 100,000 miles straight.
     If you’re considering a vehicle in this price range we urge you to set aside your preconceived notions and test drive the CDI because Mercedes has single-handedly proven that diesel cars are no longer slow, smoky or noisy. That’s a stereotype Americans will have to cross off the list.

The Good:
Diesel power with no compromises, wonderful transmission, gorgeous cabin, top-notch materials, big trunk.
The Bad:
Small wheels, last-generation nav system, $690 for paint?!
The Verdict:
We become diesel fans overnight.


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