You know a car is long awaited when it’s given an entire engine transplant before it’s even been launched. CAR first rode in the new Porsche Cayenne Hybrid back in July 2007. Two years later, it’s still not on sale and now it’s been transformed from a 3.6 V6 into the Cayenne S Hybrid toting Audi’s new 3.0-litre supercharged V6. And we’re promised that what you see here is exactly what you’ll be able to buy from next year.
We’ve driven Porsche’s new hybrid at a Bosch technology day ahead of the petrol-electric Cayenne’s launch in 2010. And don’t assume this is some nichey, low-volume sports SUV eco sop – what you see here is exactly what will underpin the new VW Touareg Hybrid and Porshce Panamera Hybrid as well – the entire engine, transmission and drivetrain will form the basis for all three petrol-electric vehicles.
Porsche Cayenne S Hybrid: the techy bit
Out goes the old VW VR6-related 3.6 V6, replaced by the silken, direct-injection 3.0-litre V6 that we’ve already come to admire in the new Audi S4. Worries before we even start it up? In our long-term test S4, we still mourn the loss of the V8 burble and are becoming worried the official consumption claims have gone equally AWOL.
Bosch has supplied the hybrid module and control unit, but not the battery packs (its own lithium ion battery joint venture with Samsung won’t produce results until 2011). The electric drivetrain sits between the V6 and the new, eight-speed auto transmission. A separate clutch between the engine and gearbox means that the Cayenne Hybrid can decouple the petrol engine entirely, running on either pure electric or corner-baiting petrol mode in full four-wheel drive. Other systems, such as the Lexus RX450h’s, effectively run the rear axle electrically.
An auto gearbox? In a Porsche hybrid?!
Yep – this is the first time I’ve tested a petrol-electric car with a full torque converter auto instead of a CVT. You notice it the moment you step on board and start up. Pull away, and the Cayenne Hybrid offers conventional gearchanges even in full EV mode. It makes for a much more conventional ‘car-like’ experience (even thought that phrase annoys me – of course it’s a bloody car!) and you won’t miss that wildly unhinged CVT racket and soaring revs one jot.
It takes a while to adjust, because the Cayenne Hybrid then changes down when you brake, even when the engine is switched off and you’re coasting along in ‘sailing’ mode. But it’s entirely in keeping with the Porsche dynamic DNA and the gearchanges are slusher-slick. It’s a healthy blend of old and new, then – and with eight ratios, the Aisin auto box is biased towards changing up early. Seventh and eight are, needless to say, overdrives.
>> Click ‘Next’ to read how the Cayenne Hybrid fares on road
So the Cayenne Hybrid (2010) has pulled away in electric mode. What next?
There are no confusing controls in the new Cayenne Hybrid. The only telltale from behind the wheel is a suitably Porsche take on the whizzy digital displays you’ll find in a Lexus, Honda or Toyota hybrid. Complete with that slightly anal, wonderfully Germanic logic and finished in on-brand typography and graphics, it tells you visually whether you’re plundering the world’s oil or electricity reserves.
Response from a standstill is wonderfully instant. The 38kW electric motor develops a fulsome 221lb ft of twist from a single heartbeat and the bulky Cayenne Hybrid veritably shoots forwards. You never quite feel the full combined effect of the V6’s 325lb ft and the electric motor – the ECU intervenes in the name of battery protection. Apparently the gearbox could take the combined 546lb ft thrust, but it’d drain your energy reserves in next to no time.
It’s a seamless system, easily the match of Toyota’s Hybrid Synergy Drive, juggling the twin power supplies with insouciant ease. And the Cayenne Hybrid has another trick up its sleeve: it can ‘sail’ at speeds of up to 75mph with the engine completely deactivated. Drive at motorway speeds, cruise downhill and the tacho suddenly sinks to zero, the V6 switches off and the central clutch isolates the engine from the internal combustion engine, killing all pumping losses and doing a passable impression of a yacht surfing on full sail. It’s calm, smooth and the engine starts in 300ms the moment you brush the throttle. Very impressive.
Ok, so the Porsche Cayenne Hybrid is a real smoothie. Does it work at the pumps?
Ah yes, the Achilles’ heel of many hybrids. Porsche hasn’t yet issued full homologated figures for the Cayenne Hybrid, but the late prototype we drove was in full production spec with all systems signed off. Only durability testing remains to be undertaken.
Porsche claims 31.7mpg and around 205g/km of CO2 for the Cayenne Hybrid. We weren’t able to verify that on our closed circuit test, but it sounds plausible. It’s some 27% more efficient than the entry-level £37k Cayenne 3.6 petrol. And you do get that feelgood glow from running around in full EV mode. Although there’s no manual selection button, the system will drive on battery power alone for up to two miles and at speeds up to 50kph (we reached an indicated 40kph no sweat).
Porsche Cayenne Hybrid (2010): the verdict
It’s such a slick operation, it’s hard not to be impressed by the electric Cayenne. It’ll cost some £50,000 (note the Cayenne S badging and competitive performance figures in our spec box) and Porsche expects it to account for just 10-15% of all Cayenne sales worldwide.
In a high tax environment like the UK, where SUVs are increasingly given the cold shoulder and Cayennes carry a stigma in some urban circles, I’d expect that to be a pessimistic forecast. Here’s a Cayenne to keep your conscience clean and engineering intrigue tickled. The only problem on the horizon? The Cayenne Diesel’s figures of £39,404, 30.4mpg and 244g/km.
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