Porsche had a stab at a hybrid Cayenne before, but it didn't get British buyers charged up. Will the second attempt spark success? Jonathan Crouch takes a look.
Ten Second Review
Porsche might well have finally figured out how to bring us a hybrid Cayenne that will tempt buyers away from diesel engines. The plug-in Cayenne S E-Hybrid is good for 416PS, features a much slicker hybrid drive system, is priced identically to the Cayenne S Diesel and can cover around 20 miles on electric power alone.
Porsche had a go at selling us a hybrid Cayenne before and, let's be candid here, it wasn't very good. When a diesel Cayenne was faster in most real world scenarios, consumed less fuel and was less troublesome to own, you have to wonder what the point of the hybrid was. Especially when you considered the fact that you could buy the diesel and 80,000 miles worth of fuel for the price of the Cayenne hybrid. It was a bit of a non-starter. The calibration of the hybrid drive system wasn't particularly good, the car often found itself in completely the wrong gear after a spell 'sailing' (where the petrol engine shuts down when you lift off the gas pedal at speed). Plus it could only cover 1.6 miles on electric power alone and the regenerative brakes were grabby and just plain weird. Therefore there was a lot to work on when setting about building a hybrid version of the latest Cayenne. The improved model, this Cayenne S E-Hybrid, now offers plug-in capability to further drive down running costs but the acid test remains. Would you choose one over a diesel?
This being Porsche, the standout number you'll naturally be drawn to is peak power, which goes up from the 335PS of the old car to a hefty 416PS now. The engine is a petrol-powered 3.0-litre supercharged V6 which then leans on a lithium-ion traction battery with an energy capacity of 10.9 kWh to drive an electric motor that's more than doubled in power from 47PS to 95PS. This enables some properly Porsche-like performance figures. Think zero to 62 mph in 5.9 seconds and a top speed of 151mph. The top speed in all-electric driving is 77mph and if you're a bit more feather-footed you might be able to squeeze 20 miles out of the batteries on electric power alone. It probably won't surprise you to learn that the plug-in elements of this model's technology are largely identical to those in the Panamera Hybrid, except that here drive goes to all four wheels and the batteries carry a slightly higher rating. Despite its weight, the low centre of gravity ensures that the Cayenne S E-Hybrid doesn't corner like a supertanker. With petrol engine and electric motor working in unison, it's respectably rapid and a lot of lessons seem to have been learned from the 918 Spyder and race programmes when it comes to finessing the hybrid drive systems. Porsche has also worked on this model's suspension geometry and endowed it with a more noticeable step between Comfort and Sport modes on both conventionally-sprung and air-suspended versions.
Design and Build
Porsche has followed a design trend that can clearly be seen through the evolution of the Cayenne's design, each generation getting a bit sleeker and more chiselled. Now we get an even sharper design with precise lines and purposefully-placed angles intended to catch the light. The front wheel arches and the bonnet are cleaner and there are now 'airblades' in the nose. These aren't hand dryers but air fins designed to funnel air to the intercoolers. Bi-Xenon headlights are standard, with characteristic four-point LED daytime running lights. Move to the back and there are three-dimensional effect rear light clusters and the brake lights carry over the design of the front LED daytime running lights with four distinctive elements. The number plate recess, boot handle and lights are now integrated more elegantly into the tailgate. The designers also re-shaped the car's horizontal lines, giving the vehicle an even more planted stance on the road. Inside, the designers devoted much of their effort to the cockpit with the fitment of a 918 Spyder-style multi-function sports steering wheel with gear shift paddles as standard. The rear seats have also been made more comfortable, and seat ventilation can now be ordered as an option.
Market and Model
Porsche has priced the Cayenne S E-Hybrid at just over £61,000, which is an identical sum to the Cayenne S Diesel, so it's very much a case of take your pick. The 385PS S Diesel is a little quicker, but what value do you place on being able to glide noiselessly around town with zero tailpipe emissions? That's actually more a kick than it sounds. Looking outside the Porsche family, there's the Range Rover Sport Hybrid to consider, which retails at a whopping £21,000 more, so it's not something most people would give too much credence to when they've sampled the Porsche. Why else would you pay that much extra for a car with 76PS less at its elbow? Standard equipment comprises Porsche Traction Management all-wheel drive, bi-xenon headlights with four point LED daytime running lights, a multi-function sports steering wheel with paddle-shifts, ParkAssist front and rear, cruise control, automatic climate control, powered tailgate, Sport button, Start/Stop technology with coasting function and a three year warranty.
Cost of Ownership
It's quite hard to compare the running costs of the Cayenne S E-Hybrid and the Cayenne S Diesel because the NEDC fuel economy test basically has no idea how to test plug-in hybrid cars and just seems to pluck a figure out of thin air. You can see their plight. If you plugged your Cayenne into a wall socket each night and then did a commute of ten miles each way to work, you might very well consume zero petrol at all. What miles per gallon figure do you quote there? Infinity? The stated combined figure is 83.1mpg with emissions of 79g/km but unlike a conventionally-powered car where you can quote a 'real-world' economy, with the Cayenne S E-Hybrid it all depends on how you charge it, how you drive it, how far you drive it and a whole host of other variables. No wonder NEDC get a bit flummoxed. It seems that industry experts are a bit nonplussed about this car's future residuals as well, with some correspondents thinking it'll fare markedly worse than the Cayenne S Diesel. I'm not so sure about that one. If Porsche have got the engineering right on this one, and I'm fairly confident they have, it ought to be one that'll retain appeal a good few years down the track. Insurance is also four groups lower than the diesel which will save a few bob.
Porsche doesn't release a clunker very often but the first Cayenne Hybrid was as close to one that they've offered in recent years. The engineering wasn't slick enough, the marketing proposition was hazy and it just didn't make the numbers for people in real world scenarios. That was 2010. A lot has been learned since at Weissach and the latest Cayenne S E-Hybrid is a car you can certainly get behind. The electric power pack is hugely more powerful and there's a useful range in EV mode. It's quicker and slicker and now makes a viable alternative to the Cayenne S Diesel for drivers who don't like oil burners. It also manages to make its key rival, the Range Rover Sport Hybrid, look comically overpriced. So, does it get the thumbs up from us? Guardedly, yes. We'd like an extended run with it because only then do you get a feel for its day-to-day practicality and how, over a series of months, your running costs will work out. It's certainly intriguing, which is more than you could ever say about its predecessor.