2011 Porsche Cayenne S Hybrid Road Test

Porsche Adds Hybrid Technology to Its Redesigned Cayenne S

Published: 01/28/2010  - by Karl Brauer , Editor at Large

Carving through the 17 sweeping turns of sinewy Barber Motorsports Park sounds like a typical day in the life of an automotive reporter; so does off-roading through 6-foot-deep puddles and up steep, muddy inclines in a dense forest. And cruising at near-highway speeds in a high-tech hybrid vehicle running solely on electricity? Sure, more and more folks are doing that every day as part of their daily routine. But what isn't so typical is the ability to accomplish all three of these tasks in one vehicle -- the 2011 Porsche Cayenne S Hybrid.

Yet that's exactly what we did during our test-drive of the all-new Porsche Cayenne in and around Birmingham, Alabama. While our track time confirmed Porsche's engineering savvy via the lighter-yet-stronger Cayenne chassis, and our off-pavement excursion validated the crossover's ability to challenge a Range Rover or Mercedes G-Class in any wilderness environment, it was the advanced drivetrain in the Cayenne S Hybrid that truly reflected just how far Porsche has moved the technology needle.

And green technology is only one element of this new Cayenne. The artisans in Stuttgart also wanted to improve the crossover's luxury quotient with an all-new interior inspired by the recently introduced Panamera performance sedan. They further sought to upgrade interior space and ride quality via wheelbase and suspension improvements. What do all these changes mean to the end user? An all-new Porsche Cayenne with an even wider range of capabilities than the current model.

Performance

Pairing an internal combustion engine with an electric motor may cut fuel use and tailpipe emissions, but it also yields two power sources where there's usually just one. This design typically means uneven throttle and braking response, but not in the new 2011 Porsche Cayenne S Hybrid. By incorporating a lightweight, modular design for the engine, motor and (all-new) eight-speed transmission, and by utilizing a dry clutch to engage or disengage the motor, Porsche has removed what it calls the "rubber-band effect" felt in most hybrid drivetrains.

We found Porsche's claims to be accurate, as the Cayenne S Hybrid delivered the most seamless power delivery we've experienced in a hybrid vehicle. The supercharged 3.0-liter V6, based on the engine from the Audi S5, provides the internal combustion portion of the equation and produces up to 333 horsepower. It's paired to a 47-hp high-torque electric motor, giving the hybrid a maximum 380-hp rating and a maximum torque figure of 427 pound-feet at just 1,000 rpm. This kind of "instant on" power imbues the Cayenne S Hybrid with substantial punch at low speeds while pushing the nearly 5,000-pound Porsche to 60 mph in 6.1 seconds.

The hybrid drivetrain is only one of many fuel-efficiency features on the 2011 Porsche Cayenne. Beyond the aforementioned weight reduction (approximately 400 pounds) and the eight-speed transmission (of which both 7th and 8th gear are overdrives), there's an automatic start/stop function to shut the engine down whenever the vehicle is stationary. This start/stop technology is actually standard across the entire Cayenne line for 2011, except in base V6 models with a manual transmission.

But while every 2011 Porsche Cayenne can shut its engine down when stationary, the hybrid model can also shut it down when the driver lifts off the throttle at speeds up to 97 mph. In this mode, dubbed "sailing" by Porsche's engineers, the dormant engine disengages from the drivetrain to reduce drag and increase fuel efficiency.

The engine subsequently springs to life as soon as the driver engages the throttle, and while it may sound unconventional, we noted no abrupt drivetrain feedback during our "sailing" adventures with the Cayenne S Hybrid. And, because accessories like air-conditioning, power steering and power brakes are powered by electricity in this model, no drivability issues occur while the engine is shut down at speed. EPA mileage figures haven't officially been released, but Porsche expects the hybrid to achieve 20 city/23 highway mpg.

With this much technology onboard, Porsche thought it should let drivers play a more active role in how the Cayenne S Hybrid operates at any given moment. That means two extra buttons in the center console near the shifter, one marked "E-Power" and another marked "Boost Mode." With E-Power, the Cayenne will stay in pure electric mode at higher speeds and greater throttle inputs, though the engine still kicks on with anything approaching aggressive driving. With Boost mode the driver can get help from the electric motor when accelerating with only 70 percent or greater throttle input (without Boost mode it takes full throttle to get additional go power from the motor).

These driver-initiated modes are in addition to the automatic features in the Cayenne S Hybrid, including regenerative braking for charging the 288-volt nickel-metal hydride battery with braking energy. There's also what Porsche calls "shift in load point" mode, which charges the battery pack by putting a light load on the engine when accelerating or holding a steady speed. These are in addition to sailing mode (coasting).

If there's a downside to all this technology, it comes in the form of increased weight. At 4,938 pounds, the new hybrid model weighs almost exactly what the previous Cayenne S weighed. But the new 2011 Porsche Cayenne S (non-hybrid) weighs 500 pounds less than before, and if you drive the two back-to-back, the hybrid's extra poundage is impossible to ignore.

That's not to say the hybrid is incapable of thrilling its occupants. With the increased wheelbase (1.6 inches), stiffer chassis (15 percent) and updated, fully independent suspension, the hybrid handles at least as well as the previous Cayenne S. However, the other new models handle better still, and offer improved steering feel via their hydraulic steering systems.

Comfort

Despite its handling capability, the new Cayenne still offers a supple ride. In spite of its supportive seats and advanced all-wheel-drive system, the hybrid model is the least driver-oriented of the new Cayenne models (meaning it's still more engaging than most luxury SUVs). Additional comments on comfort will reveal themselves after a longer, more comprehensive test-drive.

Function

The new Cayenne's longer wheelbase allows for greater rear passenger room and comfort, as does a three-position reclining rear seat that slides 6.3 inches fore and aft. These features make it easy to increase cargo capacity without folding down the seatback, though maximum cargo jumps to 62.9 cubic feet when it's time to move things instead of people. And as in many modern vehicles, thick A-pillars allow the Cayenne to pass the NHTSA's new roof-crush standards, yet they also hamper forward visibility, particularly when making left-hand turns.

Porsche gets credit for including a USB audio input and Bluetooth connectivity, as well as a touchscreen infotainment interface, as standard equipment across all 2011 Cayenne models. High-tech options range from adaptive (smart) cruise control to a lane change assistant for monitoring blind spots to Porsche's Dynamic Light system that is both speed- and steering-sensitive for improved night visibility. A Burmester high-end surround-sound system, with 16 speakers and a rear entertainment display, is available for Porsche audiophiles but comes at a staggering price of $5,690.

Design/Fit and Finish

With the Panamera as Porsche's new benchmark for luxury, the Cayenne's interior adopted many of the performance sedan's design traits. A high center console rises up to the dash for an unbroken transition between the two, and materials quality across all surfaces has clearly been raised a notch (or two).

Subtle exterior tweaks further reflect the model's makeover, with a sharper headlight/hood and sleeker roof line accented by a more pronounced "shoulder" just below the windows. The new look is clearly Cayenne, but park it next to a current model and the exterior refinements are readily apparent.

Who should consider this vehicle

With environmental awareness at an all-time high, many luxury crossover and SUV buyers are looking to maintain their vehicle choice while offering a nod to Mother Earth. The all-new 2011 Porsche Cayenne S Hybrid answers the call, providing enough performance (whether on pavement or off) and luxury to honor the brand.

Yet, as Porsche's first foray into production hybrid technology, this Cayenne displays a refinement and effectiveness the more experienced hybrid carmakers can't match. Economically it probably doesn't make a lot of sense, but welcome to the world of luxury hybrids. For customers in this market, whose concerns have little to do with financial rationale, the Cayenne S Hybrid is an excellent choice.

Others To Consider
BMW X5 xDrive35d, Lexus RX 450h, Mercedes-Benz ML450 Hybrid, Porsche Cayenne V6.

Edmunds attended a manufacturer-sponsored event, to which selected members of the press were invited, to facilitate this report.