Porsche Cayenne S-E Hybrid Review

WHAT IS IT?
Officially the greenest version of the revised third-generation Cayenne, but with plenty of performance despite the stunning fuel economy numbers

WHY WE'RE TESTING IT
To find out if it really can provide the best of both worlds – the performance of the Cayenne S and better fuel numbers than the V6 diesel

MAIN RIVALS
Range Rover Sport, BMW X5, Range Rover Sport

WHEELS VERDICT
Looks great on paper, but will struggles to get close to its amazing economy figures if you want to leave the city

PLUS: Looks, handling, comfort, performance
MINUS: Expensive, heavy, limited electric range, can’t match diesel economy on longer journeys

THE WHEELS REVIEW
It would be unfair to say the Cayenne S E-Hybrid is a one-trick pony. Like the rest of the recently tweaked-and-tucked Cayenne range it’s extremely good at everything from high-speed cruising to mild off-roading. But it will definitely be its economy numbers that win it the most attention.

The official figures border on the surreal. On the EU test cycle – which plug-ins are allowed to start with their battery packs fully charged – the E-Hybrid consumes just 3.4 litres/ 100km. This in a vehicle that has a total combined power output of 306kW and, despite weighing 2350kg, can drag its lardy arse from 0-100km/h in 5.9 seconds. Drive a hulking great SUV, save the planet, all at the same time.

But, of course, there’s a but: like all of its plug-in brethren the E-Hybrid can only deliver those numbers if you never stray too far from an electrical socket. Beyond its electric-only range of 35km, it’s just a hybrid carting around an extra-large battery pack.

Mechanically the Cayenne E-Hybrid is pretty much identical to the plug-in version of the Panamera that’s been on sale in Europe for over a year. Both share the same supercharged V6 and 70kW electric motor that is sandwiched between the engine and the standard eight-speed auto 'box. The Cayenne has slightly more battery capacity – 10.8 kW/h versus 9.4 kW/h – but otherwise the two cars are Appalachian cousins in terms of shared DNA.

The good news is the greenest Cayenne it’s no hair shirt special. Left to its own devices the e-Hybrid operates in electric-only mode at low speeds, and this makes it extremely smooth and quiet when asked to trundle. The engine cuts in as required, with the powertrain’s transition from electrons to hydrocarbons seamless. You can lock it into electric-only mode at speeds of up to 125km/h, although faster progress destroys battery range.

The rest of the driving experience is almost identical to the standard V6 Cayenne S. You can feel the E-Hybrid’s extra mass when attacking a tighter road, but it still grips and turns remarkably well for something so tall and heavy. Under extreme abuse it does wilt in a way the standard Cayenne doesn’t – with the brakes starting to fade after being asked to cope with repeated big stops. A stretch of Autobahn confirmed it’s happy to cruise north of 200km/h, little use though that will be over here…

And economy? Porsche laid on a gentle 50km test route which the E-Hybrid started with a fully-charged battery pack, the trip computer reporting 3.4 litres/100km at the far end – the award from Greenpeace is in the post. For contrast, 50km of enthusiastic caning in the same car saw the display reading 19.6 litres/100km, and brought a knighthood for services to the petrochemical industry. The truth lies somewhere between those contradictory extremes.

Porsche Cayenne S E-Hybrid
Engine: 2995cc V6, dohc, 24V, SC with 70kW electrical motor
Max power: 306kW @ 5500rpm (total)
Max torque: 590Nm @ 1250 – 4000rpm (total)
Transmission: 8-speed automatic
Weight: 2350kg
0-100km/h: 5.9sec
Fuel economy: 3.4L/100km (EU)
Price: $139,200
On sale: Now