New Mercedes-Benz S550 Plug-in Hybrid charges for extra efficiency

New Mercedes-Benz S550 Plug-in Hybrid charges for extra efficiency

The first plug-in hybrid car from Mercedes-Benz weighs 5,093 lbs., hits 62 mph in 5.2 seconds and will likely carry a price tag thousands higher than the S-Class sedan on which it is based. The German carmaker calls the S550 Plug-In Hybrid — the full name as it appears on the trunk — the first model of a new plug-in hybrid fleet. But why did it start with its largest and most expensive sedan?

Because it has to start somewhere.

The S-Class now serves as the test bed for new Mercedes technologies; systems like the nearly autonomous driving and pedestrian avoidance unveiled in the S-Class have trickled down through the entire line. With its high sticker price, Mercedes-Benz can afford to finance and test new efforts first in the S550 that it plans to implement in other, smaller models.

And as one of the few automakers that pays fines to the U.S. government for falling short of ever-increasing fuel economy standards, Mercedes has to run to catch up with its powerful but thirsty fleet.


“There’s no clear roadmap of what will happen with emissions rules," said Thomas Weber, head of development for Mercedes passenger cars, "but it’s clear that Mercedes-Benz needs to start development today."

Mercedes-Benz S550 Plug-In Hybrid
Mercedes-Benz S550 Plug-In Hybrid

The Plug-in Hybrid pairs an electric motor and a twin-turbo V-6 for a total of 442 hp with 479 ft-lbs of torque combined, a slight step down from the regular S550 with 449 hp with 516 ft-lbs of torque. The S550 Plug-In Hybrid can go roughly 20 miles on a single charge and takes 2 to 3 hours to fully recharge, depending on voltage; Mercedes-Benz is working on wireless charging that could be installed under the floor of a garage, rather than requiring the socket in the back bumper.

To boost mileage, the S550 has a haptic accelerator pedal that gives a light tap to the ball of your foot when you should ease off the gas to maximize efficiency and help recharge the 8.5 kWh battery pack mounted in the trunk. It also gives the driver a light tap when moving from all-electric to gasoline mode.

For an even greater increase, the driver can choose a new drive mode called E+. For any mapped route, E+ mode will change it to find the most efficient directions based on traffic, speeds and hills – looking for routes where the car will be flat at the end of an uphill stretch so that the battery can recharge on the way downhill.

With all this efficiency in tow, the S550 Plug-In Hybrid does sacrifice some performance over its purely gasoline-powered brother. The setup brings the Plug-In Hybrid to 0-60 mph in around 5.2 seconds while the gasoline version does it in a quicker 4.8 seconds.

Yet in a brief drive, the S 550 Plug-In Hybrid does not feel slow—in fact it’s as fast as many sports cars. It’s quick to accelerate onto a highway using the gasoline engine and the transition from electric to gasoline mode is smooth and nearly unnoticeable around town. U.S. ratings haven't been finished yet, but in European testing the big sedan gets 80 mpg, which will be considerably lower in EPA testing.

Mercedes-Benz says it expects to sell more than the 20,000 units it sold of the previous, rather unpopular S400 hybrid. In fact, the company claims that in 2014, it will sell more hybrid vehicles than all the German automakers combined. In the past, Mercedes-Benz has had a number of partnerships with battery and electric car makers like Tesla, but been criticized for not having a clear hybrid or electric car strategy. That should change, as the powertrain in the S550 Plug-In Hybrid will form the base for other plug-in hybrids for the C-Class and E-Class.

Pricing for the Plug-In Hybrid has yet to be announced, but its safe to say that it can be expected to start slightly above the entry-level gasoline S550, which starts at $92,900. U.S buyers can expect to see the S550 Plug-In Hybrid in the second quarter of 2015.

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