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2007 Mercedes-Benz E320 Bluetec Review

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SEE ALSO:Mercedes-Benz Buyers Guide

Torquey, Efficient, Teutonic Luxury
By Steve Purdy
Detroit Bureau

A 700-mile cruising range? Wow. I like that. That means fewer stops at the fuel pump, but it’ll be mighty costly to fill ‘er up. This week regular unleaded gasoline is $2.45, here in mid Michigan and diesel is $2.85. Fuel tank capacity is 21.1 gallons and EPA estimates are 27-city and 37-highway. I’m going to get through the week without having to add fuel in spite of two trips into the big city and lots of running around from my rural base of operations.

Back in the late 60s and through the 70s, my older brother, Gary, had Mercedes diesels. My favorite was his first, a powder blue 220D. He was an on-the-road sales guy and could go forever on a tank of fuel, and he could go hundreds of thousands of miles without engine attention. Yes, it started hard in cold weather, and it was a bit smoky, and noisy, and slow. And your hands would stink forever if you accidentally splattered while refueling. But it was a Mercedes with unquestioned quality and class.

One of our pals at the time, a character named Leonard, was a home builder of sorts and was proud of being able to drive his 220D from Michigan to Georgia and back on a tank of fuel each way just to select his carpets from the mill. We could do that with this E320 Bluetec if we wanted to.

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These diesel problems have all been addressed. The E320 Bluetec we’re driving this week is about $58,000. Base price is $51,000. Ours has a few options. But, of course, for an E-Class (mid size) Mercedes I guess we shouldn’t fault it for price. It’s only a grand more than the V6-powered gas E-Class. Common rail fuel delivery, turbo charging, multiple valves and other engine technology make for plenty of power and speed, more insulation has made it much quieter and there are no longer any cold-start problems. The big deal these days, of course, is emissions, especially particulates (soot) and oxides of nitrogen (NOx) . How do they clean it up? Well, let’s take a look at the “Bluetec” system. That’s the interesting story here.

Certifiable in 45 states this year (not California, Maine, Massachusetts, New York and Vermont) the Bluetec diesel has multiple scrubbers in the exhaust system - two catalysts and a particulate filter. First in line as the exhaust leaves the engine is an oxidizing catalytic converter, then a diesel particulate filter and finally a selective catalytic reduction unit for reducing NOx. When the particulate filter gets to a certain degree of saturation the engine management computer will turn up the heat of the exhaust gasses to burn those darned particles off.

Next year, there will be one more element added that will result in certification in all 50 states. Urea (not cow pee – but a synthetic urea called AdBlue – essentially nitrogen and demineralized water) will be injected into the exhaust as it leaves the manifold and will somehow clean up that last bit of ugliness in the diesel exhaust - some kind of chemical magic, I guess.

Both of these systems must start with a state-of-the-art diesel engine and must use the low-sulfur diesel fuel, now becoming available at more and more outlets. This 3-liter, V6 turbodiesel has 4-valves/cylinder and replaces the trusty in-line six Merdedes used until last year. Instead of the old-fashioned troublesome injector pump and unit injectors this new engine features a common rail fuel delivery system pressurized to 23,000-psi. The fuel injector for each cylinder is positioned exactly in the center of the combustion chamber dome for maximum efficiency. This smooth diesel with a chain-driven balance shaft makes an impressive 388 lb.-ft. of torque though only 210 horsepower. It’s the torque, of course, that gets us going so expeditiously. And, I really mean expeditiously – zero-to-60 in 6.6 seconds. Gary’s diesels couldn’t have done that even with an afterburner.

The next step in getting the power to the road is the new 7-speed Speedshift™ automatic transmission with manual mode. So many gears, so little time. Nice and smooth, it shifts quickly enough but doesn’t kick down quite as quickly by itself as I would like for back road passing. That’s what the manual mode is for. It is, however, driver adaptive. The 7-speed is not available with the 4matic four-wheel-drive, but the 4matic is not available with the diesel anyway.

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Fortunately the E-Class is due for a design update next year. Our Flint Gray sedan is so plain-looking on the outside it’s almost invisible. A redesign is in order. The evolving Mercedes design language will, I’m sure, invigorate the E-Class. Don’t get me wrong. The E-Class is plenty elegant but perhaps a bit too understated, at least for my tastes. For someone who wants the classiness of the Mercedes without calling attention to themselves, the E-Class is a good choice. It doesn’t take much to dress it up nicely though. Take a look at the “designo” edition with extra body cladding, dual exhaust, dressier wheels and special colors. It’s amazing what a little trim will do.

The ride and handling are just what we might expect from this Teutonic cruiser – tight but compliant, firm and purposeful. With front engine and rear wheel drive the E-Class features a 4-wheel multilink system with 5-arm arrangement in the rear. The entire front axle assembly, front suspension and steering gear are preassembled along with the engine. Unsprung weight is minimized using lots of aluminum. The resultant feel on the road is of great balance and poise. While it doesn’t feel like a performance car on hard cornering, it wasn’t meant to. Get the 500-hp, stiff, AMG version of the E-Class for that. This is, after all, meant to be a sedate and efficient luxury sedan.

All available chassis dynamics are standard on any of the E-Class cars: Airmatic Semi-active Suspension, Adaptive Damping, speed-sensitive steering, Electronic Stability Program, Brake Assist, Pre-Safe impending crash sensing, ABS, Traction Control. The car even comes with a system that dries the brake rotors in wet conditions.

Easing into the cabin we find the E-Class practical and elegant, certainly not flashy or ostentatious. The wood and leather trim blend easily with the plastic parts for a quality feel. Controls are easy to manage with a tactile feel of perfection. I’m not fond of the navigation system controls, just too complex and obscure, although I suppose one would get used to them in time. They are not as intuitive as they should be. Perhaps if I was German I would understand them better. The 10-way adjustable leather seats with lumbar support and 3-position memory are generous and comfortable. For a few extra bucks we can have heat and ventilation in our front seats. Feedback from all the controls – steering, brakes, stalks, and so on – are excellent. Driving this Mercedes is unusually pleasurable. I feel like I’m at the controls of a fine machine.

Warranty period is 4 years/50,000 miles. Customers can purchase more coverage.

The only time we could tell this is a diesel is on hard acceleration and at idle, when we can barely hear and feel the muffled tell-tale diesel clatter, and when we gas it up, because we have to go to the special pump. We could also tell whenever we calculate our fuel mileage, were we prone to do so.

Brother Gary would love this Benz – if he could afford it.

Steve Purdy, Shunpiker Productions, All Rights Reserved