Cape Town, South Africa - The 2018 Porsche Panamera 4 E-Hybrid is an enigma wrapped in the sheet metal of a four-door 911.

It’s a car with incredible power, a lightning quick 4.4-second 0-60 mph time, and a ridiculous top speed of 172 mph. Yet, it’s a plug-in hybrid that can run on electricity alone or be driven efficiently with the motor aiding the engine.

To show off the performance and efficiency of its new luxury sedan, Porsche invited Motor Authority to Cape Town South, Africa, where I tested both sides of the Panamera 4 E-Hybrid’s split personality.

Turbos and electrons

The 4 E-Hybrid is a second-generation Panamera that has the second iteration of Porsche’s hybrid powertrain. It replaces the Panamera S E-Hybrid and, as expected, all the technology takes a step forward.

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

It starts with the engine. A new Porsche-developed twin-turbocharged 2.9-liter V-6 replaces an Audi-sourced 3.0-liter supercharged V-6. The turbos are located in the “hot V” between the cylinder heads on top of the engine. This is the same engine that makes 440 horsepower in the Panamera S model, but the turbos are smaller and it makes 330 hp and 331 pound-feet of torque in the hybrid. The last engine produced 333 hp and 325 lb-ft.

2018 Porsche Panamera 4 E-Hybrid motor and transmission

2018 Porsche Panamera 4 E-Hybrid motor and transmission

Behind the engine is an electric motor. Instead of being wedged between the engine and transmission, it is now located within the transmission, which changes from an 8-speed automatic to a new 8-speed dual-clutch transmission or PDK (Porsche Doppelkupplungs Getriebe). The motor increases from 95 hp and 229 lb-ft of torque from the last time around to 136 hp and 295 lb-ft this time.

Total system output jumps from 416 hp and 435 lb-ft of torque to 462 hp and 516 lb-ft.

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Feeding the motor is a 14.1-kwh lithium-ion battery located in the trunk. Physically, the batteries take up the same amount of space, but this year's version packs 49 percent more power than the 9-kwh version in the outgoing model.

Porsche says the new, larger battery allows the Panamera 4 E-Hybrid to drive for 50 kilometers on the New European Driving Cycle. That translates to 31 miles, but U.S. testing procedures are more stringent, so we shouldn't expect a one-to-one relationship. However, we do know that the 9.4-kwh battery delivered 15 miles of electric range. Add another 49 percent to that number you should get about 22 miles of electric range this time around.

Porsche says the battery can be charged in 12.5 hours on a standard 110-volt outlet. Opt for the available 240-volt charger with its 7.2-watt capacity and the charge time falls to 2.4 hours.

Pick your mode and your personality

For the Panamera 4 E-Hybrid's drive route, Porsche picked a picturesque, but leisurely drive along the South African coast. It was meant to show off the car’s efficiency, but I wasn’t having it. Paired up with a pleasant Brit with the anachronistic name of Jethro, we chose the twistier route for the concurrent 911 GTS drive through the Franschhoek Wine Valley. That would give me a chance to see both sides of this car’s personality.

How the 4 E-Hybrid acts is determined by its modes. It has Porsche's usual Sport and Sport+ modes, as well as a Hybrid Auto mode and an E-Power mode. The car always starts out in E-Power, which means it will run on electricity alone up to 86 mph, provided you don’t kick the throttle down past a detent in the pedal stroke.

I ran in this mode for a while and was impressed that it had decent power to keep up with traffic and perform most everyday driving maneuvers, despite running on only 136 hp and 295 lb-ft of torque. I wouldn't entirely trust it for highway merging, but the car will start the gas engine when you go harder on the throttle and return to electric operation once you ease up.

Drive the car like this on a relaxed (or slow, but tense) commute to work, and it's a green machine.

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

While in E-Power, there are two other modes: E-Hold and E-Charge. These modes create or conserve electric power for times you might need it, such as when driving in emissions-free zones in city centers. E-Hold will hold the current level of battery charge and E-Charge will use the engine to charge the battery. Be aware that the car will run rather inefficiently in E-Charge because the engine is doing extra work to charge the battery.

Next, I tried the E-Hybrid Auto mode. In this mode, the car will seek to run the most efficiently, using the engine, motor, or a combination of the two to achieve the best fuel economy. While deep stabs of the throttle are not efficient, Hybrid Auto mode is just fine with that because it will team the two systems to give you max output when you ask for it. The last version required the throttle to be pressed at least 80 percent of the way to the floor to get the electric motor to kick in. In this mode, electric assist is available at all times.

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Opt for Hybrid Auto mode on a regular basis and the 4 E-Hybrid will be efficient for a 462-hp full-size luxury car. How efficient? We don’t know yet as EPA numbers aren’t available, but combined fuel economy in the mid-to-upper 20s doesn’t seem out of the question. For reference, the EPA gave the 2016 Panamera S E-Hybrid a 51 MPGe rating and a combined city/highway rating of 25 mpg. Expect slightly better for both ratings.

Then we arrived at the mountainous wine country roads and it was time for the Sport and Sport+ modes. That's when I got the chance to sample the Mr. Hyde side of this car’s persona. Sport mode always maintains at least a minimum battery level to ensure that there is a so-called “e-boost” reserve for aggressive sprints. Sport+ is the only way to reach the car’s top speed of 172 mph, but also recharges the battery faster than Sport. In either mode, the engine is always on.

Hammer the throttle in any model and the two power systems are blended beautifully to deliver sudden and thrilling acceleration. Power is available throughout the rev range, and the shifts through the new 8-speed PDK are quick and crisp, but not jarring.

She handles, too

The drive along the Franschhoek pass showed that the Panamera 4 E-Hybrid is a Mr. Hyde in more ways than one. It is a Porsche after all, and that means it has to be sporty. On these twisty mountain roads, this 198.8-inch, 4,784-pound car drove much smaller than its considerable size.

The car rotates around corners like its wheelbase were a foot shorter. It leans very little in turns. The steering is quick and precise, but light, and the car gathers its considerable heft quickly to attack the next turn. For reference: The Panamera 4 E-Hybrid is some 700 pounds heavier than the all-wheel-drive 4 model with the same engine.

Besides a new platform, Porsche offers some features to help the Panamera defy the laws of physics. The Panamera rides on the Volkswagen Group’s new MSB platform. It uses aluminum and high-strength Boron steel to save weight and improve rigidity. It has 8 percent more torsional stiffness than the last Panamera’s body. Every Panamera comes with a three-chamber air suspension to improve ride quality and handling. On top of those, Porsche offers, rear-axle steering, active stabilizer bars, and Porsche Torque Vectoring Plus.

The rear steering system moves the rear tires up to 2.8 degrees in the opposite direction of the front tires at low speeds to help the car turn more sharply and effective shorten its wheelbase and with the front wheels at high speeds to improve stability.

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

2018 Porsche Panamera 4 E-Hybrid

The active roll bars, known as Porsche Dynamic Chassis Control Sport, stiffen in corners to keep the car from leaning too much.

Porsche Torque Vectoring Plus uses both an active rear differential and targeted breaking of the inside wheel to send the power to the outside wheel in a corner to help the car rotate.

Impressively, the car I drove had only the air suspension. If it were outfitted with these other systems it would be even sportier. Perhaps those features could be used to make the 5.9-inch longer Executive model handle like this one.

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I did have one minor complaint, though. Braking has been a bugaboo for hybrid buyers since the advent of the hybrid, and there are some minor problems here. Like the rest of the car, the regenerative braking system is upgraded. The alternator now effectively slows the car for any braking event that is 0.3 g or less. The last model handled braking events of 0.15 g or less. That means in most daily driving the regen braking is slowing you down when you hit the brakes. Once the car reaches about 9 mph, the mechanical brakes take over.

And those mechanical brakes are big ones: 15.3-inch rotors up front and 14.4-inch rotors in the rear. In heavier braking events the mechanical and regen brakes are blended, and in all cases the brakes can feel a bit grabby and the hand-off to the mechanical brakes at low speeds can be a bit awkward. I didn't have much of a problem with the system and most people will get used to the feel, but some may not find it natural.

The verdict

The 2018 Porsche Panamera 4 E-Hybrid will go on sale this summer with a starting price of $100,650. That represents an increase of about $6,000, but you do get more efficiency and more performance. A longer Executive model will run $105,150.

If you are considering buying a Panamera 4 E-Hybrid, the mode you choose and how you drive it will determine the car's personality. Drive it hard and and outfit it with some performance features, and it can feel like a four-door 911. Charge it up and tread lightly on the go pedal, and this big, comfortable luxury sedan can be green car among gas guzzlers. It's not green at 172 mph, but it’s nice to have the option.