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Mercedes-Benz C350e plug-in hybrid has a gas pedal that pushes back

Mercedes-Benz will bring 10 PHEVs to market by 2017. The C350e is one of the first.

Antuan Goodwin

Antuan Goodwin

Reviews Editor / Cars

Antuan Goodwin gained his automotive knowledge the old fashioned way, by turning wrenches in a driveway and picking up speeding tickets. From drivetrain tech and performance to car audio installs and cabin tech, if it's on wheels, Antuan is knowledgeable.

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5 min read
2015 Mercedes-Benz C350e PHEV

2015 Mercedes-Benz C350e plug-in hybrid


Just before I was given a peek last week at the far-flung autonomous future of Mercedes-Benz, I had the opportunity to experience the brand's very near future behind the wheel of the Mercedes-Benz C350e, which should be reaching the public this fall.

Approaching the mid-sized sedan, there wasn't much that indicated to me that this was different from your standard Mercedes-Benz C300 sedan. Take a look at the corner of the right rear bumper, however, and you'll find a discreet little hatch that hides a J1772 standard EV charging port. Yes, the 2016 C350e is among the first plug-in hybrids (PHEVs) from the brand and it won't be the last. Mercedes-Benz has claimed that it will be bringing 10 new plug-in hybrid models to market by 2017.

Lift the hybrid's hood and you'll be greeted by a plastic engine cover a 2.0-liter, four-cylinder gasoline engine that's good for a stated 208 horsepower and 258 pound-feet of torque. That engine is mated first with Mercedes' hybrid power unit, an 80-horsepower electric motor that sits between the engine and transmission and adds 251 pound-feet of electric torque to the mix. Put into perspective, the C350e's electric motor alone boasts more torque than a Nissan Leaf. Total output for the plug-in hybrid system is 275 horsepower and 443 pound-feet of torque. (Note: The numbers don't add up neatly because the gasoline and electric power plants peak at different RPMs.)

The hybrid power is then sent to a single-option seven-speed automatic transmission on the way to the rear wheels.

2016 Mercedes-Benz C350e plug-in hybrid (pictures)

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Electricity for the hybrid is stored in a high voltage, 6.4 kWh battery pack that's tucked beneath the trunk floor. Mercedes says that it chose this capacity to minimize the physical size of the battery pack, but the C350e still loses about 10 percent of its trunk space in the conversion. There's still a good deal of room beneath the rear lid and the back seat's pass-through doesn't appear to be compromised.

Charging the battery happens via the aforementioned port on the rear bumper. Under optimal fast-charging conditions, the C350e can be juiced in as little as 1.5 hours, but Mercedes-Benz reckons that most users will see a 2.5 hour charging time from their home chargers. Fully charged, the sedan will be able to silently cruise for 18 to 20 miles on pure electric power if forced into its e-mode.

After a 2 hour charge, the C350e can glide for 18-20 miles under full electric power. Antuan Goodwin/CNET

The C350e features four driving modes that tweak the behavior of the sedan's steering, suspension, powertrain and climate control system: comfort, sport, sport plus and eco. Choosing the "eco" setting opens up four more sub-settings for the hybrid system: hybrid, e-mode, e-save and charge. Hybrid is the default setting that lets the computer decide the gasoline-electric mix. E-save adjusts the hybrid system's parameters to conserve battery power. Charge keeps the gasoline engine in an always-on state to actively add to the battery's reserves.

Finally, e-mode is the fully electric setting. Interestingly, the C350e is able to stay in its e-mode at speeds up to 80 mph. To help drivers to manage the e-mode, the C-Class PHEV has been equipped with a haptic gas pedal. When in e-mode, the pedal offers resistance to the driver's foot at the threshold of the electric motor's capability. I was able to push past this resistance easily, if more acceleration is desired to bring the gasoline engine into the mix. I found the haptic pedal to be much more intuitive than the "power meters" or "eco gauges" that I've often found on the dashboard of hybrid cars.

The driver can choose between four driving modes and four hybrid system modes. Antuan Goodwin/CNET

The Benz puts a lot of drive mode and hybrid settings at the driver's fingertips, but you don't actually have to use any of them. Leaving the car in its default "comfort hybrid" mode, the sedan's electronic brain seemed to do a good job of choosing the right power source for any given moment.

The standard navigation system also integrates into the hybrid system's operation, automatically optimizing the energy usage for the chosen trip. For example, the C350e can look at your route and decide to use gasoline power for the long highway stretch in the middle of your commute and save the battery power for the slow congested urban area at the end, where it can be more efficiently utilized.

The haptic pedal also comes into play when cruising. When the C350e's forward sensors detect that the car ahead is slowing down, the haptic pedal gave my foot a little double-tap to encourage me to lift the accelerator and begin to coasting early. This allows the car to take better, earlier advantage of regenerative braking versus braking aggressively and wastefully later. The "radar-based recuperation" may sound like a lot to take in, but (like the e-mode's selective resistance) I found the pedal's tapping very intuitive and much less distracting than some of the screen- or tone-based systems that I've tested previously. After an hour behind the wheel, the haptic pedal was second nature.

On the road, the hybrid powertrain doesn't draw attention to itself, performing like a big V-6, but with better than small four-cylinder performance. Antuan Goodwin/CNET

The car's on-the-road performance, while quite good, doesn't feel remarkable compared to a standard C-Class; it doesn't draw attention to itself. The hybrid system just makes the little four-banger feel like much larger engine, but without the noise and efficiency compromises that would normally come with going big. An interesting side effect of the hybrid system is that it totally smooths out the operation of the standard stop-start anti-idling system, allowing the sedan to pull away from a silent stop without the engine roughly coughing to life.

Sadly, I wasn't able to experience the C350e's sport mode on a good, twisty road due to time constraints, but I'd imagine that the hybrid handles and performs a lot like the 2015 C-Class sedan that we tested previously...only with about twice the torque on tap to balance the extra weight of the 220-pound battery pack and motor. Check our review of the 2015 Mercedes-Benz C300 for an idea of what to expect.

Available LED headlamps up the C350e's curb appeal and driver visibility. Antuan Goodwin/CNET

The example that I was provided came close to fully loaded up, featuring the full Comand connected infotainment suite, the excellent Burmeister premium audio system, and every bit of driver aid tech that Mercedes-Benz could throw at the sedan. The hybrid is also available with Benz' head-up display and LED headlamps. Again, you'll want check out our full review of the 2015 Mercedes-Benz C300 for more information about the tech.

Pricing hasn't been announced for the 2016 Mercedes-Benz C350e and neither have final EPA estimates for fuel economy. During my short time behind the wheel, I averaged about 40 mpg on a route that took me around San Francisco in moderate traffic and then down the coast at low highway speeds. We'll have to wait until the Mercedes-Benz C350e's launch this fall to gather more extensive data.