The E-Hybrid will be the cleanest Porsche Cayenne you can buy, if you remember to plug it in regularly, because it has a limited range as a full battery-electric car.
It also has the capacity to use both the electric and petrol motors to run hard, plus it has all the ride, handling, connectivity and interior advantages of the stock new Cayenne, which has just gone on sale in SA.
Forget to plug the E-Hybrid in to a power socket when it arrives here later in 2018 and you’re going to be stuck with a Cayenne that is 2,295kg and running almost completely on a 3.0l, turbocharged V6 petrol engine worth 250kW and 450Nm. Unimpressive, especially for a Porsche. Remember to charge up the 14.1kWh lithium-ion battery, though, and you’ll have 340kW and 700Nm underfoot, which is more like it and will sweep the E-Hybrid to 100km/h in 5.0 seconds.
Don’t charge and you’ll be stuck (compared with the Cayenne S) lugging around 275kg of complicated, expensive stuff that can only hurt the car’s performance and economy. Charge, and you’ll be asked to haul a cable in and out of the luggage area in all weather, with all the dirty-hands implications that are inevitable with that.
Charge, and you should get close to Porsche’s fuel-consumption claim of 3.2l/100km (or even improve on it if the commutes are short enough to do on the 44km of zero-emission, EV range, so about 25km in the real world). Don’t charge and, well, Porsche isn’t giving a fuel-consumption figure for that.
Those are the questions buyers need to ask themselves. Yes, it’s going to help assuage the guilt of driving a 2.3-tonne SUV when a 1.6-tonne wagon would clearly do the job, but how often will you arrive home from work and just not be bothered making the effort? How often will you want to roll up a dirty cable, dressed in your best suit?
Only individual buyers can answer these questions, hopefully honestly and realistically, and Porsche insists they’re answering in the affirmative a lot more every year.
There’s a reason for this. Do it right and the E-Hybrid is a terrific car. It’s not quite as composed and coherent as the borderline-brilliant (and cheaper) Cayenne S, but it’s very, very good.
Let’s begin with the basics: the Cayenne E-Hybrid rides on the same MLB Evo architecture of the conventionally powered Cayennes, which gives it access to stuff like an active anti-roll bar, rear-wheel steering, a hang-on rear diff, three-chamber active air suspension and a raft of electrickery.
It’s a significant upgrade from the second-generation Cayenne’s E-Hybrid in more ways than that, though. It’s upgraded in some E-Hybrid-specific areas. For starters, it now has a lithium-ion battery, which replaces the old nickel-metal hydride unit, and its 11kWh of usable capacity is up about 30% on the Gen II version.
The battery has eight modules, each with 13 prismatic cells, and the chemistry has changed to jump them from 24 ampere-hours to 37, so they can charge and discharge quicker. Its electric motor is a tonne stronger, too, up 43% to 100kW in its output and delivering 400Nm of torque from, effectively, zero revs per minute.
There are new strategies that govern how the car uses the electric power, including the car starting in pure EV mode every time (so it starts rather quietly). It will even reach up to 135km/h as a pure EV.
It can use the V6 to boost a drained battery, which is also the least efficient way you can drive the E-Hybrid, adding a few hundred revs to every exertion the throttle asks the engine to make. You can run it as a pure EV, a hybrid, a sports version of a hybrid or even as a V6 while you save the battery’s charge for the city you’re approaching.
It’s at its best either in its Hybrid or Sports modes, when the big brain chooses when to swing the electric motor into play, how strongly to bring it into play and how often. Sports+, most people will find, is simply too snappy on throttle response and too firm in its ride to bother with for any extended period. It’s not even the fastest way through bends, with Sport mode keeping the tyres planted on the road far better over bumpy roads.
It remains a very handy machine in the bends, attacking corners with a vigour that belies the mass moving around beneath it and the 138kg of battery pack lurking behind the rear wheels.
The steering feels well connected to the road and gives admirable feedback for a car this size and it can be hustled through corners with remarkable enthusiasm for a car that’s 63mm longer and 23mm wider than before. It helps that the active anti-roll bar can keep the body flat at up to 0.8g of lateral acceleration, but the rear-wheel steering also has a role to play.
The beauty of all the MLB Evo technology is that its pieces can’t individually be felt working by the driver (or the passengers). It just all works together to make the car do things better, as a complete car.
There are other firsts for the E-Hybrid. It becomes the first Porsche to use a head-up display, for example, and it dips in to its 3D surround view’s tech package to deliver a rim-warning system, alerting drivers who are about to kerb a wheel.
It makes other sensors double service as well, for example keeping its rear radar (mainly used for the lane-changing blind-spot warning) running for 30 seconds after the car is switched off, so it can warn of looming cars, motorbikes, bicycles or even pedestrians before you open the door.
There are new digital instrument-cluster graphics to show the electric system power bits and pieces, including the power drain or charge rates and how much range you have left. The navigation map even shows you clearly how much EV range you have in the car.
The E-Hybrid will run the Chrono Package as standard, along with delivering a boost button (in the middle of the mode switch) to add a bit of overboosting for a limited time.
The eight-speed automatic transmission (inside which the electric motor sits) is a sweetheart of a thing and you barely notice it until the car’s in Sport+ mode, and the hang-on centre differential mixes the drive seamlessly to both ends of the car, depending on when it’s needed. Again, it’s technology you don’t have to worry about, because it all just kind-of happens, and happens well.
Of the Cayenne range, the entry car hits 100km/h in 5.9 seconds, and the E-Hybrid adds a lot of weight and an enormous amount of cost for a 0.9-second improvement, using the same core petrol engine.
It’s a terrific machine, if it’s used correctly. It’s a terrific but inefficient machine, even if it’s not. If you plan to plug it in regularly, it should work well. If not, take a Cayenne S.