Porsche Panamera S Hybrid

When the 2012 Porsche Panamera S Hybrid arrives this fall, it won’t find many hybrid luxury sedan competitors. Three to be exact: the Mercedes-Benz S400 BlueHybrid, BMW’s ActiveHybrid 7 and the Lexus LS 600hL. The question is why are these four automakers even offering cars that seem so out of step with our times?

The answer is easy, they have no choice. Increased government fuel economy regulations and more stringent emissions standards are forcing all car companies to step up to the plate and produce vehicles that will meet the mandated requirements.

If you’re Porsche, you can’t walk away from being known and revered for high performance sports cars and extreme German engineering. So, without sacrificing performance, hybridization is Porsche’s first step in meeting new regulations. The company is quickly adopting hybrid technology with the Cayenne S Hybrid, the 911 GT3 R Hybrid racecar, the announced 918 Spyder supercar and now, the Panamera S Hybrid.

The Powertrain

Hardcore Porschephiles are still kicking cans over Porsche becoming integrated under the Volkswagen umbrella, but without the VW parts bin there would be no Panamera hybrid. The hybrid powertrain is nearly identical to the Porsche’s Cayenne S Hybrid sport utility, which was borrowed from VW’s Touareg Hybrid SUV. The engine, a 333 horsepower supercharged, direct-injected 3.0-liter V-6, is sourced from the Audi S4. Power to the rear wheels is managed by the same eight-speed Tiptronic S fitted in the Cayenne models, with a wide range of gear ratios. Unlike gasoline-powered Panameras, the Hybrid edition does not offer all-wheel drive.

The Porsche full hybrid system can power the sports sedan by the gasoline engine only, the electric motor only or a combination of both. Fitted between the V6 and transmission is a 47 horsepower (34kW) electric motor that brings total output up to 380 horsepower. When it comes to torque, the engine generates 325 pounds-feet, but with the 221 pounds-feet created by the electric motor, Porsches says maximum torque climbs to 428 pounds-feet.

The system’s unique feature is a hydraulic clutch between the engine and motor that disengages the engine so it can shut down under light loads. The electric motor then takes up the load until the engine restarts. Porsche engineers call the result “sailing”—for the quiet sensation of speed using only electric power. This operational mode is engaged when the driver lifts off the accelerator at highway cruising speeds, up to a maximum of 103 mph. Combine the sailing capability with the top two overdrive gears of the transmission and the benefit is a gain in highway fuel economy, a result not associated with hybrids.

Porsche says the Panamera can operate on electric power alone for a little over a mile up to a speed of 53 mph. To maximize electric efficiency, a driver activated E-power button blunts throttle response and delays activation of the gas engine.

As in most hybrids, the electric motor also restarts the engine, and recharges the battery pack. The electric motor is connected to a 288-volt nickel metal hydride (NiMh) battery pack that’s fitted behind the rear axle, under the rear cargo area. This is a simpler and less costly system than Toyota’s Hybrid Synergy Drive, but it comes with drawbacks, one being that the vehicle can’t use the engine to recharge the batteries while running on electric power at the same time.

Exterior

Panamera’s two-box exterior shape flows from two predetermined goals: a four-door that looked like a Porsche and interior space efficiency. The finished product resembles a stretched Porsche 911 with four doors, spacious room in the rear cabin and almost 16 cubic feet of cargo space in the rear. The design is contentious, with one automotive critic saying that “It’s as if one of those limousine manufacturers who stretch Hummers and Cadillac Escalades got hold of a 911—all that’s missing is a wet bar and colored lights underneath.”

That’s brutal, but not completely unfounded. Yes, it’s quite clear that the Panamera’s design was influenced by the revered 911 sports car. This includes a hood that is lower than the front fenders, the absence of a conventional grille above the bumper and prominent bulges around the rear wheels. But when you add the rounded hatchback style in the rear, the proportions are not harmonious, and the car becomes awkward looking from certain angles.

In defense of the looks, it does help to see the Panamera in person. Photographs can’t quite capture the essence of the shape and they distort some of the lines. Apparently consumers have taken a close look at the super luxury car and liked what they saw; the Panamera has become Porsche’s top-selling vehicle in the U.S., and globally, pushing the Cayenne out of the way.

Like other carmakers that have hybridized an existing model, Porsche adds hybrid-specific badges to the Panamera. For owners who prefer to be discrete about their greenness, Porsche dealers can remove them without leaving any evidence on the front doors and rear deck that could reveal an inner passion for the environment.

Interior

Following Porsche tradition, the key fits in the ignition slot to the left of the steering wheel. But tradition ends there. The Panamera has the most opulent Porsche interior ever. It has a private jet ambience with a quality that equals some of the most luxurious cars in the world. “The interior is fantastic—one of the best marriages of high-tech, simple luxury and exquisite craftsmanship we’ve seen,’ is Popular Mechanics magazine’s observation.

A full-length center console divides the cabin into four separate seating positions yet has a sense of intimacy. Up front the feeling is akin to a sports car cockpit while rear cabin passengers can luxuriate in limousine-like spaciousness. The four bucket seats are faultless for either energetic driving or family trips. But Business Week pointed out a drawback to the Panamera’s cabin layout, “The cabin feels as roomy as its competitors. The bucket-style rear seats are spacious and comfortable, even for passengers over 6 ft. tall. The downside is that the Panamera seats a maximum of four people, vs. five for its BMW and Mercedes competitors.”

From the driver’s seat, eyes are drawn to the handsome five-gauge instrument cluster. A glance to the right locates the center console’s master control. While it has a dizzying number of switches, they are logically grouped and easily mastered. Navigation information is viewed on a screen in the center of the dash.

The Hybrid introduces some subtle changes. An E-Power gauge, showing whether the battery is charging or depleting, replaces the oil level reading on the leftmost gauge. A condensed version of Porsche’s Hybrid Management system is added to the digital multi-information gauge. It indicates which of the Panamera Hybrid’s six driving modes is in operation. Another change is the addition of the E-Power switch to the center console.

Panamera’s hatchback design makes it impressively practical. Space behind the rear seats expands from 11.6 cubic feet to 40.7 cubic feet—down 3.7 cubic feet from the non-hybrid model—, which rivals space found in many crossover vehicles. And getting max cargo space is simple: push a button on each seatback and they lower to reveal a nearly flat load surface. While the hatchback design has benefits, like the Prius, rearward visibility in the Panamera is dismal and is compounded by the large rear pillars. Suggestion: order the optional back-up camera.

On The Road

The Panamera S Hybrid is as much a Gran Turismo sports sedan as its gas engine counterparts are. That Porsche believes the Panamera hybrid’s performance warrants adding the “S” badge says volumes about the car. The engine and motor’s combined 428 pounds-feet of torque at just 1000 rpm propels the sedan from 0 to 60 mph in 5.7-seconds—just a half-second off the pace of the V-8 powered Panamera S. Those numbers are accomplished by what Porsche calls Boost mode — the engine and electric motor deliver power at the same time to the transmission. To unleash this combined power the battery must be suitably charged, so the feature is available for short periods.

Reviewers are not only impressed by the hybrid Panamera’s power delivery, but give it high marks for its handling. Motor Trend said, “The Panamera S Hybrid shows the type of composure we’ve become accustomed to in other versions. Supple enough to be comfortable, but feeling tight as a drum in transitions, the Panamera continues to show that four doors need not be boring.” Car and Driver stated that the Porsche Hybrid badge was no joke and, “The Panamera S Hybrid possessed great poise with just a touch of understeer when pushed hard. The electrically-assisted steering is perfectly weighted and helps make the big-bodied Panamera feel smaller than it really is.”

The Popular Mechanics’ reviewer summed things up by saying; “Its best trick is being an excellent luxury sports sedan and an excellent hybrid at the same time—something unseen until now.”

Economics

Porsche says the Panamera S Hybrid is its most fuel-efficient vehicle of all time. EPA testing is not completed so that pronouncement is based on the New European Driving Cycle (NEDC), which gives more weight to start-stop driving than the EPA test cycle does. The NEDC numbers translate to an approximate 33 mpg combined city/highway fuel economy. Comparing the NEDC Cayenne S Hybrid numbers with the EPA rating it seems reasonable that the Panamera Hybrid’s combined fuel economy will be around 25-26 mpg. That’s not headline news fuel economy, but it’s a significant 5-6 mpg improvement over the V-8 Panamera S.

Priced at $95,000, the hybrid system appears to add $5,200 to the $89,800 gas-only Panamera S. But that premium includes some expensive goodies that cost extra on the V-8 model—air suspension, adaptive shock absorber, Bi-Xenon headlights and navigation system to name a few. Porsche has sold nearly 22,000 Panameras in the U.S. since its late 2009 introduction and sales are on the upside this year. The company says it expects 10-15 percent of buyers to choose the hybrid version. But with all of the standard equipment on the hybrid Panamera, why buy the V-8?