REVIEW: 2015 Mercedes-Benz S500 Plug-in Hybrid

REVIEW: 2015 Mercedes-Benz S500 Plug-in Hybrid

2015 Mercedes S500 Plug-in Hybrid AMG Line L

Mercedes-Benz have long been strong advocates of electric technology, albeit in a more subtle way than just coming straight out with an all electric car. Instead, so far they have preferred to dabble with hybrid powertrains and leave pure electrics to their other brand interests, such as smart. However, the newest addition to the S-Class range is a plug-in hybrid (PHEV). What this means is the refined experience of being sat in a prestige barge just got that little bit more luxurious and does away with obscenities such as vibration and engine rhythm.

This new found luxury does come at a price though, namely in the shape of a heart stopping £90. For that money, you would expect at least two powertrains and a whole host of goodies and luxuries you could never be without. Of course, it delivers all these things and when you put your finger on the calculate button, the new S500 Plug-in Hybrid can make some financial sense too – depending upon where you live.

If you’re a businessman travelling around the countryside, this car is unlikely to benefit over others in the S-Class stable, such as the S300 BlueTEC Hybrid. However, should you travel a lot within a city environment where stop & start are the order of the day, this new PHEV may save you a small fortune… the same small fortune Mercedes are asking from you to make the initial purchase! The S500 Plug-in Hybrid range starts at £87,965 but is eligible for the governments plug-in car grant scheme which removes a healthy £5,000 off. However, as with all S-Class it is the optional extras that really set the car apart. Unfortunately, extras are on the pricey side with a simple rear arm rest fridge costing more than £1,000. It is with this in mind that you must approach an S-Class an be wary that the optional toys inside will likely cost a small fortune, yet offer the best the automotive world has to offer. Our test car, an AMG Line L variant, came to an eye watering £111,265 after all the bells and whistles had been attached. These include the very helpful 360º overhead view camera, which is a god send when aiming to park such a long car, and a plethora of comfort options such as fragrancing for the interior and even more cosseting seating.

Driving and Performance

Driving a car like this, one should remember that a passenger in the rear of the car may be present, so an exuberent driving style is more likely to get you sacked rather than be applauded. As such, smooth driving is what this car should achieve, and it does so with ease. In slow and heavy traffic, the electric motor offers the driver plenty of pace to keep up with all but the most eager undertaking obsessed cyclist. As progress improves however, the 3.0 litre V6 cuts in with a subtle burble and assists the electric motor in achieving torque fuelled acceleration akin to a much larger capacity V8. The engine choice is perhaps a slightly odd one, given the S500 name badge yet makes complete sense when you get into performance figures and look at the point of the cars existence. 333hp is produced from the twin-turbo six, in tandem with the electric motor’s 116hp (85kW).

These combine to offer 479lb ft torque which is enough to propel the S500 PHEV from 0-62mph in 5.2 seconds and onwards to a limited top speed of 155mph. There is a neat and easy to read gauge on the dashboard which helpfully informs the driver as to what the status of the powertrain is; electric only, regen and engine revs. A little grey bar and an obvious step in the accelerator peddle ensure electric only driving can be achieved without the vulgar cutting in of a petrol unit too. Press beyond the step and the petrol engine seemlessly kicks into life and the vehicles total power is revealed. However, when coming to a stop the engine cut out was a little on the harsh side, although I’m certain a passenger in the rear absorbed in today’s headlines would not have noticed.

The S-Class controls are unhindered by the additional battery weight and the sure-footed stance of the wide body make the cars presence on the road assured. Manoeuvring is kept reasonably light thanks to decent power steering, and controls fall to hand without so much as having to bend your elbow. Only a little road noise from the 19″ AMG alloys disturbed the calm of the otherwise cathedral quiet interior.

As is typical in most PHEV’s, the S500 sports four driving modes; EV, Hybrid, Charge and Save – or words to that effect. EV mode does what it suggests, and prioritises electric driving over the petrol engine but as aforementioned, should you press the pedal beyond the step, the engine power can still be accessed. Hybrid mode simply asks the car to decide which power delivery is best for the moment and for the most part I found it got it right, with only a couple of occasions in traffic where the engine breathed life unexpectedly. Charge and Save are two mostly pointless modes which are perhaps only good for a chauffeur driving to collect their passenger and wanting to show off the electric drive without having first depleted the power en-route. Charge mode simply uses the petrol unit to charge the battery and Save mode aims to use the petrol unit to maintain whatever level of charge remains in the battery. The thing is, it is a plug-in hybrid vehicle, so why would you use expensive petrol to charge the battery when electricity is that much less expensive?

2015 Mercedes S500 Plug-in Hybrid AMG Line L


Charging the S-Class is a slightly odd experience. Mercedes have located the charging socket in a corner of the rear bumper, meaning that it is always covered in road filth. Once the hatch is open, you’re presented with a seven-pin Mennekes socket much like you would find on most German EVs. However, perhaps a slight oversight is a lack of CCS socket to accompany the seven-pin as this would have enabled the PHEV to charge that much faster when on the road. Although in truth it is unlikely to see an S-Class driver at a motorway service station sat waiting while they charge their 18-mile range, the future proofing element of it would be advantageous. Even in the scenario where the car is being charged at a home or garage environment, the seven-pin socket will generally only ever see a maximum of 7kW pumped through it using a wall box. This should charge the 8.7kWh lithium-ion battery from 0-100% in a little over an hour. Had that been using CCS on the other hand, that time would tumble down to 15-20 minutes. The car is supplied with all the cables necessary and the massive boot has plenty of space within which to hide them when not in use too.

Specs at a Glance

Price (from): £87,965
Price (as tested): £111.265
0-62mph: 5.2 seconds
Top Speed: 155mph (limited)
Economy (official): 100.9mpg
Economy (as tested): 23.4mpg
CO2: 65g/km
Engine: Twin-turbo 2,996cc, V6, 24 valve – 333hp
Electric Motor: 116hp (85kW)
Battery: Lithium-ion 8.7kWh
Charge port: 7-pin Mennekes type
Kerb Weight: 2,215kg
Turning Circle: 12.3m
Transmission: 7G-Tronic Plus seven-speed automatic

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