We’ve already found out that the Mercedes E-Class is good, the main reason it being an E-Class. But only recently, Mercedes introduced EQ-Power. The combination of a new four-cylinder diesel and an electric motor gives us the E300de. Let’s see how this drivetrain behaves in an already proven platform.

Since I’d like to point out the brilliance of the drivetrain, let’s start off explaining the lay-out of this car. The E300de is basically a regular E220d with a transmission-mounted electric motor and a battery pack in the rear. Other than most parallel-hybrid powered cars, the E-Class remains rear wheel driven. To get technical right away: by utilizing the transmission in combination with the electric motor, you’ll experience some incredible mechanical advantage. This results in a torque multiplication that equals the transmission ratio. The gear reduction won’t let you gain any power, but since the transmission has 9 gears, the instant 1st gear acceleration is huge. In some circumstances, you can feel the gearbox shift when driving solely on electricity, an experience I’ve never had before since most electric motors drive wheels instead of transmissions. Unlike the AMG E53‘s EQ-Boost, the electric motor found in the E300de delivers an additional 122 hp and 300Nm. 

Torque is your friend

When the diesel engine and electric motor team up the combined power output is 232 kW or 315 PS. This makes you accelerate from zero to 60 mph in 5,9 seconds. That’s not blisteringly fast, but keep in mind that this car tips the scale at 2140 kg. However, it’s the torque that characterizes the E300de’s behavior and there’s 700 Nm’s of it. The ease at which this drivetrain operates is spectacular. Every single Nm you ask for is delivered to you effortlessly and that’s what makes this drivetrain so comfortable. 

Umweltfreundlich

After driving it for a week, I found myself switching between two different driving modes: Sport and Eco. Sport mode is cool and gives you access to its peak performance when the diesel and electric motor are working together. It biasses the diesel engine and only uses electricity for quick accelerations. It’s Eco mode however where this driveline really shows off what it’s capable of. The seamless transition between the engines is remarkable. Sometimes you have to take a glance at the rev counter to see whether the diesel engine is on or you’re just driving full electric.  

Mercedes claims that the E300de should be able to reach up to 166 (!) MPG, 1.7 liters per 100km. To achieve this, you should use the full potential of the battery and let the energy recovery system do its job. The recovery gauge challenges you to drive as economical as possible. I put it to the test myself and achieved an impressive 2.0 l/100km over an 81.2 km trip, of which 43.1 km were fully electric. This results in a respectable 5.2 l/100km when the diesel engine runs without help from the EQ-powerplant. Longer trips however, take that magic 1.7 l/100km closer to around 5.5, since there’s no more electricity to bring that number down.

Kinetic energy recovery 

Energy recovery is something to point out because it actually extends your electric range by more than you’d expect. A flick of the left pedal while being easy on the brakes during deceleration results in somewhat heavier engine braking. Doing so, you can see the live recovery gauge raise into the green area immediately. So glad I found one way to make use of the E300de’s massive weight. Besides that, the navigation system also has a few tricks up its sleeve. It seems to communicate with the recovery system, shutting down the diesel early before braking points to maximize energy revovery. 

Built for comfort

One thing that stands out is the quality of the interior. Combine this with the ease of the drivetrain and you end up with the sheer comfort this E300de offers you. The driver’s assist and extreme sound isolation add that extra bit of tranquility in the cabin. It’s not sporty in any way. Although it has the power and mechanical grip, the steering wheel tells you that the E prefers to go straight out. So, comfort it is than.

As you’d expect from the E-Class it is a spacious car. Perhaps not as spacious as a non-hybrid since the battery pack takes up quite some liters of trunk space (480L instead of 640). Interior space is good, the same in the back seats. The seating position is low but the view out is decent. The camera system helps you maneuver in tight spaces, even in the dark resolution still holds up nicely. 

Final verdict

Its appearance and CO2 emission of a mere 44 g/km make you think that it has an annoying tendency to be politically correct. The E300de does its job without drama. However, it’s far from boring. Being an automotive engineering student, it’s very interesting to see new technologies being applied. Most of its intelligence is tucked away so nicely that you barely notice that the car is doing its utter best to deliver the driver a comfy ride. In short, the E300de is a clever concept, enveloped in a premium car. It’s not just about the numbers that make this car interesting, it’s the addition of the hybrid powertrain that suits the character of the E so well.

Special thanks to Ward for some wallpaper material.