Loosely translated from the original German

More comfortable and safer

Given today's traffic density, there is an increasing demand for reducing vehicle operation to the essentials. An automatic transmission relieves the driver considerably in this situation, but with a conventional design cannot meet the driving dynamics requirements of a high-performance car like a manual transmission. Agility in automatic transmissions can only be achieved through intelligent electronic control with practical shifting strategies.

Porsche engineers have developed a transmission with a shifting philosophy that meets all requirements: the powershift dual-function automatic transmission with torque converter and four gears, controlled by the so-called "Porsche Tiptronic". As an alternative to automatic operation with active electronic control of the shifting characteristics, manual gear changes are also possible, similar to a conventional manual transmission. The Tiptronic S also offers manual gear shifting control on the steering wheel.

Driving dynamics at the touch of a thumb

In the Porsche 911 Carrera from model year 1994/95, the new Tiptronic S with two shift paddles on the steering wheel spokes also ensures a particularly impressive driving experience. This attractive optimization step is combined with unusual shifting comfort. The control is only activated in the manual gate of the selector lever, the functions of which remain unchanged.

With the hands in the correct grip position on the steering wheel, a light push of the thumb upwards is enough to shift up - a tap downwards to shift down. The placement and design of the shift paddles marked with the word "Tiptronic" and the clearly noticeable pressure point, in combination with the electronic monitoring of the transmission control, prevent incorrect gear shifting. The current gear selection is also visible in the instrument cluster.

Driving pleasure with the gearshift control on the steering wheel takes on new dimensions, the Carrera seems even more agile. The quick reactions of the transmission (without interrupting traction!) triggered by a light pressure of the thumb create a very spontaneous driving impression. Subjectively, a significant increase in driving dynamics is registered. Since the hands remain on the steering wheel, Porsche takes another step towards active safety with the Tiptronic S. Driving comfort also increases. Associations with the transmission controls of today's racing cars automatically increase the driving pleasure with the powershift dual-function automatic transmission. Even for convinced manual transmission enthusiasts, the Porsche 911 Carrera with Tiptronic S can be considered a serious alternative.

Highest standard

The electronic control of the hydraulically operated gearshift processes is now standard in automatic transmissions. There are usually two programs that can be selected with a switch: "E" for economical driving and "S" for a more sporty variant. The Porsche Tiptronic, on the other hand, offers, apart from a special warm-up map, five programs stored in the control unit with different characteristics, including for the torque converter lock-up. They are each called up automatically in accordance with the driving style and route profile.

The range of shift points that the Porsche Tiptronic can achieve ranges from a particularly economical variant for a particularly quiet driving style (early upshifts, low engine speeds) to the highest driving dynamics with the engine revved in the gears and early downshifts to the shorter gears. The driver's influence is crucial. Reasonably rapid accelerator pedal movements, for example on a winding road, as well as frequent, forceful acceleration result in the shift maps changing gradually, possibly up to the extremely dynamic variant - and vice versa. Kickdown, fully depressing the accelerator pedal with downshifting to the lowest possible gear, can also be called up at any time, but is not necessary for a more aggressive driving style.

The Intelligent Shift Program (ISP) in the Porsche Tiptronic S contains, in addition to the five automatic maps, the following special features:

• a warm-up program with suppression of early upshifts for a rapid rise in temperature;
• an active shift that immediately shifts the shift points into the dynamic map when the accelerator pedal is moved quickly;
• suppression of overrun upshifts when the accelerator pedal is lifted quickly, for example before bends;
• a brake downshift to the next lower gear for better engine braking effect;
• a gear fixation in bends to prevent upshifts;
• a step upshift from the lower gears, especially after a previous active downshift, no immediate gear change to the highest gear;
• hill detection to drive in low gears for as long as possible on inclines or declines;
• a slip upshift when braking on slippery roads (wet, snow) to improve the lateral guidance of the drive wheels and thus driving stability.

When the gear is engaged, the idle speed is reduced to 700 rpm. Depending on the driver's wishes, the vehicle starts off in first or second gear. When the throttle is light (throttle angle less than 30 degrees), the Tiptronic starts in second gear in an environmentally friendly and economical way. These measures reduce the frequency of gear changes, offer the best parking comfort and reduce the tendency to creep to a desired level that is advantageous for driving in convoys.

All automatic functions are monitored by numerous sensors and activated immediately when required. The measured variables are throttle position and speed, engine speed, driving speed, lateral acceleration, longitudinal acceleration and deceleration, the brake pedal and the oil temperature in the engine and transmission. The computer continuously sums, filters, averages and weights the measured values to evaluate the incoming signals and provide a logical response.

Optimization in the new 911 Carrera

With additional Tiptronic shifting strategies in the new 911 Carrera (993), further optimization of environmental compatibility, exhaust emissions and comfort has been achieved. In addition, however, a characteristic is offered - for example, with the downshift when braking into curves - which corresponds to driving practice with a manual transmission. This is also achieved by closing the torque converter lock-up clutch as early as possible in second, third and fourth gear. A corresponding torque converter map is responsible for this in each shift map. This enables a reduction in consumption and a better engine braking effect, as well as maximum driving performance.

The Tiptronic far surpasses today's usual control technologies for automatic transmissions in terms of scope and effect - it sets standards. According to the Weissach technicians, only the powerful and intelligent Tiptronic control actually meets all the requirements of a modern automatic transmission for Porsche sports cars.

The assessment is even more convincing, of course, when the selector lever is pushed from the automatic to the manual gate. This opens up the additional possibility of helping the desired driving dynamics to jump (gear) either from the steering wheel or directly with the gear lever. Tapping the Tiptronic selector lever forward in the manual gate results in an upshift, tapping it backwards engages the next lower gear.

For safety reasons, protective functions are activated at the engine speed limits: downshifts, for example from a high speed level, are only accepted when this is possible without endangering the engine. As an over-revving protection, an upshift is carried out automatically when accelerating in an emergency. In the idle speed range, if no shift signal is received, a downshift is carried out automatically to prevent the engine from stalling. All accepted shift commands can also be implemented without any problems.

Transmission technology with tradition

Porsche set milestones in the transmission sector back in the 1970s with the PDK transmission, which can be powershifted without interrupting traction thanks to a double clutch. The Tiptronic S continues this tradition.