Test Drive: 2007 Mercedes-Benz E320 Bluetec

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Photo Gallery: 2007 Mercedes-Benz E320 Bluetec

“The world’s cleanest diesel engine,” has made its Canadian debut in a car that many also view as “the world’s classiest luxury sedan.” The E-Class is the classic Mercedes-Benz sedan, combining style, luxury, safety, handling and performance with a sumptuous ride.

Bluetec is the first (and currently only) passenger car diesel engine to meet California’s super-strict emission requirements. Winner of the AJAC “Best New Technology” award and the “World Green Car” award, this engine sets a new benchmark for diesel engines.

While the E-Class styling changes are subtle for 2007, major action has been going on under-hood and the E now comes in five versions. Starting prices are considerably lower (by about $10,000) than last year, and other than Bluetec and the E63 AMG, all versions come with 4Matic all-wheel-drive.

Looking at the rest of the line-up there’s a new E280 4-Matic that comes with a new 3.0-litre V6. The E-350 4-Matic still has a 3.5-litre V6, and a new E550 4-Matic comes with a new double overhead cam 5.5-litre V8 that generates 382-horsepower.

The E320 Bluetec’s 3.0-litre V6, with engine cover removed. Click image to enlarge

Diesel engines inherently produce less carbon monoxide and carbon dioxide than gasoline engines, however they do produce hydrocarbon emissions in the form of soot, and the higher combustion pressures and temperatures also generate more nitrogen oxides.

E320 Bluetec, which replaces last year’s E320 CDI, is a common-rail direct-injection V6 turbo-diesel which has a more complete combustion process and after-treatment devices in the exhaust system. A particulate filter traps soot and an oxidation catalyst deals with leftover hydrocarbons. The system automatically does a (stove-style) self-clean periodically – this generally takes place when the vehicle is cruising on the highway. A third device in the exhaust stream is an advanced-technology NOx storage catalyst.

Although not in this year’s E320, the Bluetec system can also be equipped with an AdBlue injection module that makes it as clean as a state-of-the-art gasoline engine.

2007 Mercedes-Benz E320 Bluetec. Click image to enlarge

Already in use in Europe, it uses a water-based urea solution that’s metered into the exhaust. Carried in a separate small tank, AdBlue is refilled during routine scheduled maintenance.

The 2007 E 320 is one of the most streamlined sedans on the market, with a low 0.27 coefficient of drag, and its distinctive twin oval headlamps make it instantly recognizable. The ’07 is slightly longer and wider than the ’06 model and it has some minor styling changes.
The front bumper and grille now have a pronounced V-shape and the headlamps have transparent louvers in the top sections. More pronounced side skirts and restyled side mirrors, rear bumper and taillights complete the minor makeover.

Inside, the new dash has an attractively curved walnut wood strip that sweeps into the door panels and blends into the centre console. Tasteful chrome trimmings abound and where there’s plastic it has a nice appearance and a soft-touch finish.

2007 Mercedes-Benz E320 Bluetec. Click image to enlarge

A concealed CD player is a very cool James Bond-like feature: press a button and a dash panel moves out and up to reveal the six-disc player. It’s powered by mini electric motors and after about 30 seconds of non-use the panel automatically closes.

I loved the perforated black leather upholstery on the generously sized but also very supportive seats. The power adjustments for the front seats are on the door panel, a traditional Mercedes placement that’s extremely user friendly. And these adjustments include power head restraints.

Rear seats that fold-down to expend the cargo area have another interesting feature. When you release the seatback, after flipping the cushion forward, the front seats automatically move forward to provide drop-down space.

2007 Mercedes-Benz E320 Bluetec. Click image to enlarge

There’s plenty of passenger space in the rear. Three head restraints are provided and they have a unique hide-away feature. It allows the driver better rear vision and it’s activated with the press of a button on the dash.

Eight airbags are standard: dual front airbags, front and rear side-impact airbags and roof mounted drop-down curtain bags are on both sides. A Pre-Safe system, unique to Mercedes, also prepares both the passengers and the car when it senses that a front or rear impact is imminent.

The lower anchorages for a child seat were particularly easy to use, but the opposite goes for the top anchors. To attach the top tether you need to release the seatback, pull the seat forward to expose the anchor, feed the tether strap between the head restraint and then push the seatback into its locked position. Once in place, however, it was a good installation.

To truly enjoy the E320 you have to take it to the highway, and the longer you spend in it, the more you’ll enjoy it – guaranteed! A supple suspension, stable yet responsive handling and an ultra quiet cabin put the E320 in the elite cruiser category.

The underlying mechanical magic is a double-wishbone front suspension layout with a unique two-piece lower wishbone and an all aluminum five-link rear suspension that’s a patented Mercedes design.

Although related, the Bluetec engine is a little louder than the V6 CDI diesel. It’s more noticeable during low speed driving, but I didn’t find it objectionable. On the plus side, the Bluetec is more responsive and its fuel economy is outstanding.

Accelerating from 0-100 km/h takes less than seven seconds, according to Mercedes, and pretty good for an engine that redlines at 4500 rpm. Fuel economy is comparable to an efficient economy car, and on the highway it can go up to 1,000 kilometres between fill-ups.

2007 Mercedes-Benz E320 Bluetec. Click image to enlarge

While the horsepower numbers may not look too exciting, this engine can produce up to 400 lb-ft of torque. That’s amazing pulling power and you really appreciate this attribute when you encounter a steep hill. Smaller hills you don’t even notice, as your foot doesn’t have to move on the gas pedal.

The Bluetec engine requires ultra-low sulphur diesel fuel, which is now readily available in Canada. However, it would also benefit, performance wise, with a fuel that has a higher cetane rating, which is the diesel equivalent to gasoline’s octane rating. Canadian diesel has a low cetane rating, which varies between 40 to 47, when compared to 51 to 55 rated European diesel.

A seven-speed automatic transmission completes the E320’s truly outstanding drivetrain. Gear changes are super slick, especially in the higher gears. The shift characteristics can also be changed from Comfort to Sport at the push of a button and it allows full manual gear selection.

Comparatively, the ’07 E320 Bluetec offers good value for money too, when you consider that its base price of $68,100 is $7,250 less than last year’s E320 CDI.

In my opinion, the Mercedes-Benz E320 Bluetec hits a home run for clean diesel vehicles. The first of many, I hope!