First Drive: 2016 Mercedes-Benz S 550e plug-in hybrid

It may seem presumptuous, or perhaps even unfair, but I don't imagine Mercedes-Benz S-Class owners care too much about how much gas they burn.

If you can afford to spend north of $100,000 on a car, I've always maintained, then you're probably not going to sweat over fuel economy.

So why, pray tell, does the 2016 Mercedes-Benz S 550e plug-in hybrid exist?

Well for starters, emissions and fuel economy regulations around the globe are growing increasingly stringent, and automakers are leaning on a combination of alternative fuel and small displacement offerings to offset the rest of their lineups.

(Hence the 0.9-litre three-cylinder powering the 2016 smart fortwo and the massive V12 under the hood of the Mercedes-Maybach S 600.)

The second reason is that electrified rides are very much in vogue these days among society's elite thanks to cars like the Tesla Model S.

And finally, because it will sell.

Cut through all the hybrid mumbo-jumbo—85-kW permanent-magnet AC synchronous electric motor; 8.7-kWh lithium-ion battery pack—and this is still a Mercedes S-Class, and one riding on an extended wheelbase no less, which means plenty of luxury appointments for driver and passenger.

Heated seats and steering wheel alone don't cut it in a sedan of this stratum, so heated armrests front and rear count as standard equipment, while the $6,100 Premium Package adds so-called "Passion" Nappa leather throughout the cabin, and "Climate Comfort" front seats.

The former means silky smooth surfaces, though the light grey colour of our tester's seats showed signs of denim staining, while the latter means, among other things, air-actuated bolsters that hug tighter to keep you firmly planted through corners—very cool.

A Burmester surround sound system, six-disc DVD changer, massaging front seats and push-button rear window shades are also along for the ride.

All that luxury means this behemoth tips the scales at 4,883 lbs., compared to a curb weight of 4,696 lbs. for the non-hybrid long wheelbase S 550.

An extra 187 lbs. doesn't seem that bad until you consider the latter is saddled with the extra weight of all-wheel drive, something not available on the hybrid S-Class.

The additional heft and rear-wheel drive configuration don't hamper the S 550e too much in a straight line, with the car running from 0 to 100 km/h in 5.2 seconds, less than half a second slower than its V8-powered sibling.

It's in normal driving circumstances around town that all two-and-a-half tons can be felt, with the hybrid powertrain's twin-turbocharged 3.0-litre V6 and electric motor feeling a little sluggish off the line.

Make no mistake, the S 550e will go when asked to, with a combined system output of 436 horsepower and 475 lb.-ft. of torque, it just takes a little more skinny pedal to do so.

The best way to inject some giddyup into the mix is by switching the powertrain setting to Sport, which kicks the engine on and sharpens throttle response, but defeats the purpose of driving a plug-in hybrid.

No matter the drive mode, the S 550e's air suspension can be set to Comfort or Sport, the latter adding stiffness to decrease body roll.

Going against my usual desire to drive in Sport everything all the time, I found myself sticking to the Comfort suspension setting, which absorbed bumps with atypical aplomb, and the E-Save drive mode to maximize efficiency.

And it worked.

On a 300-kilometre journey, most of it on the highway, I managed about 10.3 L/100 km, all while sitting about as comfortably as your grandfather in his favourite armchair.

Granted, that's about 0.6 L/100 km worse than the combined fuel consumption advertised by Mercedes, but it's pretty darn close, and impressive considering those combined numbers came with only a 15 per cent charge in the battery when I set out.

But about that battery.

A casualty of the additional efficiency is in the trunk, with the battery pack mounted behind the rear seats, reducing cargo capacity to 395 litres.

That compares to as much as 530 litres in non-hybrid S-Class models, and 470 litres in the much smaller Mercedes CLA-Class.

While the reduced cargo room probably isn't a deal-breaker for potential private owners, it could deter future fleet owners from adding these otherwise opulent rides to their rosters.

What it lacks in trunk space the S550e more than makes up for in rear seat legroom, with the more than five inches of extra wheelbase compared to the standard S-Class all winding up behind the front seats.

Should you need to add even more luxury, the Premium Rear Seating Package can be added for a cool $5,700.

So what's not to like about the S 550e?

Truthfully, not a whole lot—or at least not any more than the rest of Mercedes' lineup.

Because like its stablemates from Stuttgart, the S 550e's COMAND infotainment system lacks a touchscreen interface, leaving users to navigate through its multiple pages using a console-mounted rotary dial and touchpad.

The car also makes do with awkwardly placed heated steering wheel and cruise control switches that are mounted on the steering column behind the signal arm and aren't visible to the driver.

But perhaps the biggest downfall of the S 550e is its radar cruise control system, that works tremendously well—when it works.

Because, as I discovered while travelling along the Queen Elizabeth Way between Toronto and the Niagara Region during a bout of sleet, any blockage of the system's many censors renders the car's cruise control function useless, leaving me lusting for the tried and true manually-controlled setup.

Outside of those small snafus, this is still an S-Class, and with it's $117,300 MSRP coming in at $2,200 less than that of the non-hybrid, long wheelbase S 550, it's priced right, too.

Base price: $117,300

As tested: $133,250

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Test Drives2016 Mercedes-Benz S 550e: Green Executive
The electrification of the large luxury sedan segment is gaining momentum, as Mercedes-Benz has introduced the S 550e plug-in hybrid this year, joining a growing family of S-Class models that includes hot-rod AMG variants and the ultra-luxury Mercedes-Maybach S 600. It will go head to head with the BMW 740Le, …