What is it?
Thanks to its growing acceptance in North America, it’s now got to the stage where hybrid drive is the rule rather than the exception in the luxury car ranks, as the Audi A8 e-tron, BMW 7-series Active Hybrid, Lexus LS600h and Mercedes-Benz S400 Hybrid all attest. No surprise, then, to see Porsche looking to get in the petrol-electric action with its new Panamera S Hybrid.
What’s it like?
Set to join Porsche’s local line-up in June, the big four door liftback, borrows its advanced driveline from the Cayenne S Hybrid. It pairs the 328bhp supercharged V6 petrol engine with a 47bhp electric motor that draws energy from a 1.7kW/h nickel-metal hydride battery mounted in the floor of the boot.
As a full hybrid, both can power the new Porsche depending on the driving conditions, with the electric motor claimed to provide zero emission capability up to 53mph in ideal conditions in eco power mode. For full performance potential, the two pool their reserves to provide a total of 375bhp along with a sturdy 427lb ft of torque –19bhp shy but 58lb ft more than the 4.8-litre V8 petrol-engined Panamera S.
The hybrid system favours electric propulsion from start up, resulting in an eerily quiet character as you set off. It requires a smooth driving technique and loads of patience, but be prepared to forego acceleration away from the lights for more leisurely progress in city conditions and you can eek out a reasonable range on the electric motor alone in city driving. Not that we managed to get anywhere near the 1.2 miles claimed by Porsche.
At higher speeds there’s a more regular interaction between the petrol engine and electric motor, but the transition from one to the other is absolutely seamless. Under constant throttle load, it is the petrol engine that does the majority of the work, providing both power to the rear wheels and, via the electric motor which works like an alternator when not in operation, a small charge of electricity to top up the battery when required.
Push hard and you’re rewarded with an impressive turn of speed. At 1980kg – a good 80kg more than the Panamera S, there’s a lot of mass to shift. But with all that torque developed at just 1000rpm, the Panamera Hybrid possess a solid in gear performance, as revealed in its 50-75mph split of just 3.9sec.
The Panamera S Hybrid uses a different gearbox to the rest of the Panamera line-up save the soon-to-be-launched Panamera S Diesel. The eight-speed torque converter equipped automatic, the only choice of gearbox available, is equipped with Porsche’s fiddly steering wheel mounted shift buttons for remote shifting. Unlike the four-wheel drive Cayenne S Hybrid, though, drive is sent to the rear wheels.
More than straight line performance, though, it is the overall efficiency that Porsche champions the most. With automatic stop/start, brake energy recuperation and an advanced clutch arrangement to disengage the engine on a trailing throttle, the big four-seater is claimed to return 39.8mpg (7.1L/100km/h) on the combined cycle, for an overall 167g/km. Option it up with low rolling resistance tyres and economy improves, with an official 41.5mpg (6.8/100km) and 159g/km.
To put that into perspective, the Panamera S achieves 22.6mpg (12.5L/100km) and 293g/km in base six-speed manual rear wheel drive guise.