Driving The Mercedes S Class 580e PHEV

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The Mercedes S Class 580e PHEV is perhaps the world’s largest and most expensive plug-in hybrid passenger car. It lists for $122,550 not including destination charges or $126,850 in AMG trim. It comes with a turbocharged inline 6 cylinder engine that provides 362 horsepower and 369 ft-lb of torque. The engine sends power to all four wheels through a 9 speed automatic transmission that distributes it via the well known Mercedes 4Matic drivetrain.

An electric motor adds 148 horsepower to the mix. No torque numbers are given by the company for the electric motor. Nor does Mercedes specify the size of the battery, but it must be considerable. Trunk space in the non-hybrid S Class is nothing to write home about at around 13 cubic feet but the 580e PHEV makes do with just 8.1 cubic feet of trunk space. The Tesla Model 3 has 19.8 cubic feet behind the rear seats — more than double the big Merc. The company describes its plug-in hybrid technology this way.

“Advanced 4th-gen Plug-In Hybrid technology delivers numerous electric-car benefits while retaining the convenience of a gasoline engine. The compact electric motor can deliver a substantial boost in power and torque, or let you drive up to 46 miles on battery power alone. Charging can come from the gas engine and regenerative braking, or plug it into an ordinary AC outlet to go from 10 percent to fully charged in just 2.25 hours. Optional DC charging can go from 10 to 80 percent in 20 minutes.”

Apparently , Mercedes elected to place the battery in the plug-in hybrid model underneath the trunk. Autoblog staffer James Riswick found there was not enough height available to accommodate a standard grocery bag. 580e owners will need to make do with soft sided luggage on road trips.

Trunk space aside, Riswick found to his surprise he preferred the 580e PHEV over the fully electric EQS. For one thing, although Mercedes says the car has an electric only range of 46 miles, his example showed 60 miles of range on a full charge. That’s enough for 2 or three days of normal driving for most folks, which means this 208.2 inch long Mercedes could be driving on electrons instead of molecules most of the time.

There are a number of CleanTechnica readers who are Chevy Volt owners, a plug-in hybrid with 55 miles of range. They report the gasoline engine in their cars rarely gets activated except on trips. Of course, the secret to getting the most out of any PHEV is to plug it in when needed. Riswick says there is DC fast charging option available for the 580e but thinks it will not get used often enough to justify the $500 extra cost.

Mercedes S Class 580e PHEV Specs

Mercedes says charging speed using an AC outlet tops out at 11 kW — enough to charge the battery from 10 to 100 percent in 2.25 hours. If the car is equipped with the DC fast charging option, it can accept 60 kW of power (about the same as a Chevy Bolt) and charge from 10 to 80 percent in 20 minutes. The car uses the CCS charging standard.

EPA fuel economy is listed as 20 mpg/53 MPGe in city driving. The numbers for highway driving are 29 mpg/48 MPGe. Neither will set any records for a plug-in hybrid automobile but it seems unlikely anyone who would drop $125,000 on a car like this is too worried about fuel economy. Perhaps there are prestige points down at the club for having a PHEV.

The driver can select from 3 driving modes. One is pure PHEV — the car runs off the battery until it is depleted. Only then does the engine kick  in. There is also a hybrid mode. The conventional powertrain has a small electric motor of its own, making it a mild hybrid when in operation. There is also a “hold” setting that saves the battery for use later so you can drive normally on the highway while saving the charge in the battery for later.

Driving in electric only mode, Riswick says, “The initial feel of acceleration is perfect for an S Class — smooth, torque-rich and utterly quiet. Push a little harder, though, and…..that initial torque burst quickly fell off a cliff as the electric motor revealed that it’s only working with 148 horsepower. As I was in (electric only mode), the car tried its best for a beat just to make sure I really was all-in on this “accelerating quickly thing” before bringing online the complicated inline six.

“Thankfully, that inline six sounds great, with a pleasing muffled snarl. No mooing CVT business as in the Lexus TX 550h+ plug-in hybrid I drove before the S580e. Mercedes pegs the 0-60 time at 4.4 seconds, but you’d need to be in Sport for that with all power sources primed for business.” So if you are doing the stop light grand prix or need to merge with swift moving traffic, EL (for electric only) mode is not your best choice. EV drivers, of course, are not required to make such adjustments while driving.

Riswick was pleasantly surprised to find the plug-in hybrid S Class does not feature the full width hyper-screen available on the EQS. Instead, it has a generously sized touchscreen that can be oriented vertically or horizontally and does an excellent job of displaying relevant information clearly and logically, unlike many cars today.

Ambient lighting options abound with 64 available colors. Mercedes has several pre-configured lighting schemes, including one called Miami Beach that sends a flood of alternating hues of pink, purple, white, and teal throughout the cabin of the car, a party trick that Riswick’s three year old son found quite enchanting. Older drivers may too.

The Takeaway

The business case for the S Class 580e PHEV is a little hard to understand unless it is meant to appeal to traditional Mercedes customers who simply cannot bring themselves to trust a fully electric battery operated car but want to dip a toe into the EV revolution. One supposes that being cosseted by all the usual Mercedes Benz S Class attributes, such as rapid heating and massaging front seats and an ionizer that purifies the air inside the car while adding an assortment of soothing fragrances, make a person forget all about how the car is powered and just want to enjoy the ride.

Hopefully, owners won’t forget to plug in once in a while but it’s our guess that many simply won’t be bothered after the first week or so, which makes the purpose of this car more difficult to discern. Perhaps noblesse oblige sums it up best.