As luxury brands try to appeal to the eco-conscious crowd (and meet upcoming CAFE regulations) we're going to see a lot more diesel or hybrid offerings. Right now Mercedes and Audi are vying for the title of best luxury brand use of a diesel engine outside the traditional SUV segment. At the moment, Mercedes is winning.
Audi hasn't offered a TDI engine in a car other than the ancient A3 hatchback for U.S. buyers while Mercedes currently offers a diesel in both the E- and S-class. As much as I enjoy hatchbacks, a mid- or fullsize sedan seems like a much more credible luxury product. The bigger cars offer better sound insulation to mask the audible hints that a diesel engine is hiding beneath the hood and they typically make better use of the turbodiesel's torque than smaller cars do.
From behind the wheel, the E350 feels slower than an E550, but it doesn't feel like a slug. I appreciate the smooth power delivery from the 7-speed automatic transmission and the ultra-long cruising range the Bluetec engine and 21.1-gallon fuel tank provide.
There are still a lot of people in the U.S. that want nothing to do with a diesel car, no matter how good the modern diesel powerplant is. Those folks are in luck now that BMW, Lexus, and Infiniti all offer midsize luxury sedans with a hybrid powertrain. Will Mercedes end up offering a hybrid E-class in addition to the diesel version, like it does with the S-class?
Phil Floraday, Senior Web Editor
The differences between the gasoline-fed Mercedes E350 and the diesel-powered E350 BlueTEC are much smaller than I expected. The gas-powered car receives EPA fuel economy ratings of 20/30 mpg (city/highway), while the BlueTEC returns 21/32 mpg. The fuel savings between the two models are minimal at best, especially when you consider that diesel fuel often costs a bit more than gasoline. When you factor in the $1200 price premium for the BlueTEC model, it's clear that picking a diesel Mercedes E-Class isn't automatically a money-saving proposition.
As to performance, there's very little separating the cars: Mercedes says the E350 hits 60 mph in 6.5 seconds, while the BlueTEC takes 6.7 seconds. The difference, of course, is that the BlueTEC offers 400 lb-ft of torque, making for instant and seamless passing even at highway speeds.
While there is a tiny bit of clatter and rattle from the turbodiesel V-6 at idle, it's only really noticeable if the radio is turned off and you're paying attention. Most of the time, the diesel E350 is as refined and comfortable as the gasoline model we drove not long ago.
Jake Holmes, Associate Web Editor
I hopped in the E350 BlueTec for a harried trip from downtown Ann Arbor to the Detroit airport. As usual, I was running late, and I also had to stop for a quick errand on State Street in the heart of the University of Michigan campus. Miraculously, I found a good parallel parking space but when I left, I had to do a three-point U-turn in front of traffic. Shifting from drive to reverse to drive while maneuvering the E350 was very slow, and if you think this was frustrating for me, let me tell you, the guy whose path I was blocking was even more frustrated and let me know about it. Whoops, sorry.
Once I was on the freeway, I blasted along at 80 to 90 mph with complete composure and utmost serenity. There's a great view through the windshield of the E-class, and it's easy to place the nose of the car in relation to the road. Speaking of the nose, this car is a little nose-heavy compared with other E-class sedan models, no doubt due to the heavier diesel engine. At 4059 pounds, the E350 BlueTec weighs 234 pounds more than its gasoline-engine sibling, and I suspect that most of that weight is over the front wheels. You get used to it, and once you're bombing down the freeway, which is where the E350 BlueTec shines anyway, you'll hardly notice the extra weight.
Joe DeMatio, Deputy Editor
I picked up this car at the airport after having spent a week in Florida driving a Chevy Cruze rental car, after which the Mercedes E350 BlueTec definitely looked inviting. The fact that this Mercedes is a diesel is pretty much a non-event during casual driving. The engine only produces 210 horsepower, but the surfeit of torque mostly makes up for that, and in most instances the car doesn't feel as if it's lacking in power. From inside the cabin, there is no audible diesel clatter; you'll only hear it if you open the window, which I was not about to do in 30-degree February weather.
As the price of gas continues to go up, it's going to be more incumbent on automakers to offer viable, high-mileage alternatives to internal combustion gasoline engines. Mercedes has chosen to offer diesel, and, while a 25-mpg combined rating doesn't sound all that impressive, it's actually quite good for a sedan in this category. Plus, with a 21-gallon tank, the E350 BlueTec offers the possibility of a 500-mile-plus range. At least that way, the pain of paying $80 to $100 per fill-up will at least occur less often.
Amy Skogstrom, Managing Editor
The E350 BlueTec is a tough sell for several reasons: It's priced higher than the regular E350, it's fuel economy is only marginally better than its gas-fed counterpart, and average fuel costs for its owner will be higher because diesel fuel is generally more expensive than gasoline. In addition, its hybrid competitors, the Infiniti M35h and the Lexus GS450h, promise much better fuel economy -- combined figures are 29 and 31 (estimated), respectively -- and give up little in terms of performance. The upcoming E400 hybrid -- scheduled to hit the market in the second half of 2012 -- will give the brand a competitor to those two from Japan, but with an estimated 27 mpg it still might leave Mercedes to play catch-up.
Jennifer Misaros, Managing Editor, Digital Platforms