On the road
Equipped with the $1320 Sport Chrono Package Plus, the Panamera offers three dynamic modes (normal, sport, and sport plus) to modify the engine, transmission, stability control, and suspension character. BMW's Driving Dynamics Control adds a fourth setting, comfort mode, and offers a broader bandwidth in varying the ride character. Despite that, with the BMW in its stiffest setting and the Porsche set to its normal mode, the Panamera is significantly more buttoned down. Body roll in the Gran Turismo is present in any quick turn, regardless of the setting, while the Panamera always remains flat and poised.
While both engines are rated at 400 hp, they're not quite equals. With two turbochargers mounted to its V-8, BMW's 4.4-liter musters 450 lb-ft of torque. Seamless, authoritative thrust is cushioned by the silky yet responsive eight-speed automatic transmission. With a wide plateau of torque available, shifting up early or neglecting to drop down that final gear isn't cause for concern.
Porsche's normally aspirated 4.8-liter makes 369 lb-ft of torque and pulls just as smoothly but issues a fierce bass growl in place of the BMW's subdued mechanical symphony. The raw vocals of the Porsche V-8 reiterate that this engine wants to be worked hard, with the revs kept as close to redline as possible. Hammering down the winding roads, we're glad to have the steering wheel shift buttons to manage Porsche's seven-speed, dual-clutch transmission. Even if they're a bit clumsy to learn, at least they allow you to keep your hands on the wheel. By contrast, manual shifting in the BMW is only available via the console-mounted shift lever.
While the Porsche lacks the BMW's grunt, its greater body control and more capable handling would likely make it faster around a track. Still, the BMW surprised us because it's no less engaging than the Porsche. Part of that, though is a weakness of the Panamera, which has a minor case of Nissan GT-R Syndrome. This is the phenomenon that afflicts incredible performance cars boasting uncanny 0-to-60-mph sprints, lateral grip, and lap times, yet failing to engage the driver the way we expect from a sports car. In the Panamera, the steering lacks the satisfying feedback cherished in Boxsters and 911s. The wheel still offers good feel, but the heavy weight masks some of the communication.
Returning to more relaxed settings and backing off the throttle, we rolled through rural downtowns and flowed with highway traffic to get a better feel for how these cars perform as luxury cruisers. Porsche's dual-clutch transmission is gentle when swapping gears, but a friction disc doesn't leave the line as gracefully as a torque-converter automatic. To compensate, the Panamera's transmission starts in second gear as long as the selector is left in automatic and you haven't activated sport plus mode. While its ride isn't harsh, the Panamera also transmits smaller impacts with more frequency and road noise than the BMW. For relaxed cruising, we'd pick the BMW hands down.