COPENHAGEN, DENMARK – By 2020, Mercedes-Benz plans to comply with the EU fleet emissions requirement of 95 g/km of CO2. It’s strategy? Hybridisation and, ultimately, zero local-emissions operation. The S500 Plug-in Hybrid (PIH) is but the first of a number of plug-ins planned by the company for release pre-2020. Following our first drive of the “cleanest” large Benz yet, it’s crystal clear there will be very little compromise for motorists and a whole lot to gain.
The claimed figures are astonishing: it emits just 65 g/km of CO2, uses a mere 2,8 litres/100 km and can reach 33 km on electric drive only (without any energy recuperation), yet sprint to 100 km/h in a scant 5,2 seconds. On performance alone, Benz says it matches the V8 turbopetrol-powered S500, yet its running costs will be but a fraction of the V8’s. In theory, it should perform similarly to a vehicle running eight cylinders, in mixed use consume as much fuel as one with four cylinders and often use no petrol at all.
In assessing the claims, there’s one important aspect to remember: the New European Drive Cycle (NEDC) favours plug-in hybrids because the electric range (33 km in this case) is fully incorporated into the calculation. Therefore, the headline figure of 2,8 litres/100 km is optimistic if a driver’s commute stretches far past the electric motor’s range.
Yet, on our initial launch drive (about 15 km) from Copenhagen’s airport to our hotel in the congested centre of the city, not once did the V6 engage (the vehicle was set to E-mode). The next day, on a mixed route that took in a large number of highway stretches and congested secondary roads, one journalist travelled almost 60 km on battery power alone (made possible by lightfooted driving and energy recuperation). Our test vehicle’s overall average according to the vehicle’s trip computer was 7,2 litres/100 km across more than 160 km. The system therefore works, and really well; the transition between the V6 and electric motor is seamless (and considerably better than in the S400 Hybrid – coincidentally, the best-selling S-Class model locally).
In fact, if you follow the guidance provided by the vehicle through the haptic accelerator pedal (it creates an artificial detent to alert the driver as to when the petrol motor will kick in), on a commute of roughly 30 km and less you may never need to employ the V6. The lithium-ion battery has an energy content of 8,7 kWh, can power the vehicle up to a speed of 140 km/h and be fully recharged through household mains in less than four hours. Next year, Benz will also offer an inductive-charging system; you’ll simply place the charging pad on your garage floor, follow the guides on the vehicle’s trip screen to position the vehicle’s charge point above the pad, and leave the battery to reload.
Drawbacks to the S500 PIH? It’ll cost the same as the normal S500 when it launches here early next year, yet lacks that vehicle’s creamy delivery and sonorous exhaust note. A more significant one is the fact that boot space had to be sacrificed to accommodate the batteries above the rear axle. The luggage bay failed to lengthways swallow my cabin-luggage case; a problem my VW Golf long-termer didn’t have when I arrived back in Cape Town.
But these are acceptable compromises considering the potential lean running and brilliance of the powertrain. The S500 PIH is certainly the best hybrid vehicle I’ve driven and confirms that satisfying motoring and sensitivity to the environment – and consciousness of our severe impact thereon – don’t have to be mutually exclusive.
Service intervals: according to onboard computer
