Shift This: A History of Porsche’s Sportomatic, Tiptronic, and PDK Transmissions

As a company, Porsche consistently finds itself caught in a tug-of-war between honoring its heritage and placing its sports cars at the bleeding edge of progress. Take the 911: Its engine is still in the wrong place and a Porschephile from the ’70s, transported directly to 2013, could still recognize today’s model as a neunelf at a single glance. Yet Porsche has continued to innovate and transform its icon in other areas, and through the 911’s many iterations the car become more luxurious, safer, more powerful, better handling. But going beyond exorcising the 911’s handling ills, offering leather-lined cup holders, and essentially perfecting the flat-six engine, Porsche’s march of progress is perhaps no better illuminated than in its automatic-transmission developments.

Faced with trying to satisfy both self-shifting die-hards and those disinterested in learning how to heel-and-toe—with a thirst for motorsports success also key—Porsche’s preferred solution has been the semi-automatic transmission, or what many today refer to as an automated manual or “manumatic.” Porsche’s first such transmission, Sportomatic, found fans among racers and left-foot-braking aficionados. Later, the dual-clutch PDK hit the racetrack long before reaching a production car. Tiptronic, Porsche’s other manumatic effort, was implemented largely as a stopgap measure between the demise of Sportomatic and volume production of PDK. All three transmissions pushed technical boundaries, and brought lazy-driving ease to generations of 911 drivers. Read on for a brief history of each gearbox, which we offer as part of our celebration of the 911’s 50th anniversary.

With its quintessentially space-age name, Sportomatic provided a nifty answer to a question seemingly no one was asking in the mid-1960s. It was an era when sports cars had shift-for-yourself transmissions—end of story—but the Germans saw a need to help in those times when even the hardest-core sports-car enthusiast grew weary of clutching in and out through heavy traffic.​

Curiously, Porsche described Sportomatic as an “automatic” transmission, even though it had no fully automatic setting. A modified four-speed 911 gearbox, Sportomatic was essentially a manual with a vacuum-operated single-disc dry clutch. A torque converter replaced the flywheel and existed both to smooth the transmission’s electro-mechanical shifts and to allow the car to remain stationary with the clutch engaged. When a driver grabbed the shift lever, the clutch would disengage, re-engaging as soon as one’s hand was removed from the stick. To change gears, the driver needed only to move the lever to the desired gate and let go of the knob.



The “gears” were labeled L, D, D3, and D4, and although Porsche suggested using L only for steep grades, it was, essentially, first gear. (We found in a 1971 test that using L helped acceleration.) Gears D, D3, and D4 were really the transmission’s second, third, and fourth speeds, and there was even an automatic-like “park” setting enabled by a pawl that both engaged and locked a countershaft gear. Sportomatic-equipped 911s were, as you might expect, somewhat quirky: As on other early 911s, there was a secondary hand throttle between the front seats to adjust the engine’s idle speed to prevent random stalls, and we found in our contemporary test that you could easily overrev the engine by accidentally touching the shift lever or not lifting from the throttle during an intentional shift event. An innovative yet flawed first step, Sportomatic’s last gasp wasn’t heard until 1980. The technology received only one update along the way, in 1975, when Porsche stripped it of one forward gear due to the torquier nature of the 911’s more-flexible 2.7-liter flat-six.




This 1991 911 Carrera 2 is equipped with Tiptronic—can’t you tell?


Following the demise of Sportomatic, a small cadre of Porsche engineers sought to continue development of automated manual transmissions over the next decade. But those efforts were largely ignored in favor of Porsche’s early dual-clutch PDK program for racing and, well, the general lack of interest in Sportomatic. Enter the Tiptronic. When developing the 964 911, Porsche turned to ZF to supply a fully automatic transmission. But an average slushbox just wouldn’t do, and so Porsche cooked up a unique protocol for the transmission’s brain. Monitoring throttle position and movement, engine and road speed, ABS activation, and fuel-delivery sensors, the four-speed automatic “adapted” to a driver’s style by choosing among five available shift maps depending on the data it received.



Critically, Porsche’s algorithm also included a manual override, accessible via a secondary up/down gate for the shift lever or by sliding the lever directly to positions 1, 2, 3, or D. Tiptronic was hardly perfect—it automatically upshifted before redline when using the shift gate, it couldn’t blip the throttle on downshifts, and it debuted in the U.S. with a $2950 price tag—but it was an improvement over Sportomatic. The shift lever’s push forward for upshifts, pull backwards for downshifts design was another hiccup; the PDK transmission in Porsche’s race cars used the opposite—and in our opinion, better—orientation, with forward taps actuating downshifts and lever pulls commanding upshifts. Later, Tiptronic-equipped cars inherited confusing steering-wheel-mounted thumb switches for up- and downshifts that survive to this day on some automatic Porsche models. Paddles are better, and it seems the company finally agrees, as we have heard that the thumb switches soon will go the way of Sportomatic.

• Instrumented Test: 2014 Porsche Cayman S PDK Automatic
• Instrumented Test: 2014 Porsche 911 GT3
• Tech Dept.: A Tale of Two Seven-Speeds, Manual and PDK

Don’t be fooled by that introduction year for the production PDK transmission—the super-quick-shifting dual-clutch automatic has been in Porsche’s parts bin for more than 30 years. PDK stands for Porsche Doppelkupplungsgetriebe, or Porsche “dual-clutch transmission.” Incorporating two concentric shafts, one for even gears and the other for odd gears, and each driven by its own clutch, the transmission’s key appeal to Porsche’s race maestros was that it starts to engage the next gear as soon as the clutch on the previous gear’s shaft starts to disengage, allowing a continuous flow of engine power and keeping the firm’s turbocharged race cars in the boost. It first appeared in a testing capacity as a five-speed in the 956 race car in 1983 before later migrating to the 962 (pictured above), in which it won its first race at Monza in 1986.

The transmission was a complicated monster. The 962 race cars had a clutch pedal for launching the car from rest; a complex array of electrohydraulic actuators handled shifting and clutching duties once underway. Drivers expressed frustration at sequential shifting—so, only being able to move up and down one gear at a time—but they could preselect other gears using a steering-wheel switch. At the time, driving with PDK was just as mind-consuming as operating a manual.



Besides requiring a learning curve, PDK was only reliable in the sense that it would reliably explode every so often, chucking shafts, gears, actuators, and the like all over the racetrack. It’s said that each time Porsche tracked down a problem and fixed it, something new went wrong. This character flaw ultimately delayed its deployment in a production car for a number of decades, although that’s not to say Porsche didn’t try and put the PDK in customers’ hands before then. There were several attempts, from a test fitment to a 924S to a production-intent integration of PDK into the 944 Turbo. A 968 equipped with PDK was nearly readied for sale before ZF’s Tiptronic was called in to pinch hit, and a stillborn successor to the 959 (dubbed 969) with PDK was killed a year before going on sale for 1991. Showroom availability of the Doppelkupplungsgetriebe wouldn’t happen until the mid-cycle refresh plans for the 2005 911, Boxster, and Cayman, this time featuring seven forward gears. The ’box was subsequently added to the Panamera (that specific unit is pictured above), adapted into the seven-speed manual offered in today’s 911, and offered as the sole transmission in the 2014 911 GT3. It continues to impress with its lightning-quick shifts and near-telepathic rev-matching ability.



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