Mercedes-Benz E350 BlueTec Six-Month Review and Report

By Jonathan Spira on 21 May 2012
  • Share

The Mercedes-Benz E350 BlueTec has been in our long-term test fleet for a over six months at this point and, now that the car has passed 4396 miles (7075 km), it is fitting to look back.

It’s noteworthy to mention that everyone at The Diesel Driver wants to drive the E350.  It has a certain je ne sais quoi about it, perhaps thanks to its combination of refinement, comfort, luxury, and handling.

Personally, I’ve become rather addicted to the massage function that the seats offer but the E350 is the first long-term car we’ve had which has safety features that not only protect the vehicle’s occupants but actively take measures to avoid accidents.  Yes, we’ve seen a few of these features before.  But it’s the way the features all work together that makes it worthy of note.  We’ll visit this matter shortly.

One thing we’ve found is that this car sips diesel fuel.  While it’s rated at 21 mpg (11.2 l/100 km) city and 32 mpg (7.35 l/100 km) highway, it consistently beats those figures.

In addition to its frugal diesel engine, the Mercedes-Benz E350 BlueTec can thank the laws of physics for its excellent fuel economy.

The base European model has a drag coefficient of 0.25, making it the world’s most aerodynamic and hence slickest luxury sedan. The U.S. model, with its wider tires, has a drag coefficient of 0.27.

Most cars today have a drag coefficient of 0.30 to 0.35.  To put this in perspective, the 1934 Chrysler Airflow, the first U.S. automobile to be designed for improved aerodynamics, had a drag co-efficient of 0.5, which was at the time considered a major improvement over the two-box design of most cars.  The original Volkswagen Beetle, which is not at all boxy, had a drag coefficient of 0.48, and a boxy but contemporary Hummer H2 had a drag coefficient of 0.57.

The improved aerodynamics not only mean excellent fuel economy but also less wind noise at highway speeds.  The body of the E-Class is 30% stronger than its precedessor and the use of lightweight, high-tensile-strength steel for the body with aluminum for the doors, hood, and trunk means improved safety in the passenger compartment as well.

The overall fuel economy after our drive from Stuttgart to Maastricht was 31.78 mpg (7.4 l/100 km), more than respectable, but on our first significant drive once the car made it to the U.S., from New York to Kennebunkport, Maine, we saw fuel consumption of 37.93 mpg (6.2 l/100 km).

On a 357-mile (575-km) drive lasting six hours with an average speed of 60 mph (97 km/h), the fuel economy was 36.2 mpg (6.5 l/100 km).

The Mercedes has two trip computers and we left the second one running after the Kennebunkport drive, for a total of 3,287 miles (5,290 km) and 104 hours of driving.  Much of this was urban and the E350 used 7.5 l/100 km (31.4 mpg).  The average speed was 33 mph (53 km/h).

Click here to continue to Page 2Distronic Plus, Active Lane Keeping Assist, Active Blind Spot Assist, and Attention Assist

Pages: 1 2 3