Tiptronic
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It has been suggested that this article or section be merged with manumatic. (Discuss) |
Tiptronic, is a type of manumatic automatic transmission developed by Porsche, and used in its vehicles, and those of its licensees.
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[edit] Overview
Tiptronic is a registered trademark, owned by German sports car maker Porsche, who license it for use by other manufacturers, such as Land Rover and the Volkswagen Group (Audi, SEAT, Škoda and Volkswagen). However, many people (erroneously) use the term to refer generically to any automatic torque converter transmission that incorporates a manual upshift/downshift feature.
[edit] Human machine interface
A Tiptronic transmission can operate in the same manner as a conventional type of automatic transmission, but also offers the driver an additional method of manually overriding the automatic shift changes. By moving the shift lever into a second shift gate, equipped with two spring-loaded positions: "upshift" and "downshift", the driver takes over most of the gear shifting decisions, which would ordinarily be performed by the transmission's computer. For example, this allows delayed upshifts for increased acceleration, increased engine braking, gear holding in curves, downshifting before passing, or early upshifting for cruising. On some models, the upshift and downshift operations can also be controlled by push-buttons or "paddle shifters" installed on the steering wheel, with an optional display in the instrument panel indicating the current gear selection. Since adding Tiptronic to a (semi-)automatic transmission involves an additional shift gate into the computer and update to the transmission software, it is inexpensive and lightweight to implement.
Although Tiptronic transmissions allow the driver a certain measure of discrete control, the Tiptronic design is implemented using a torque converter like other automatic transmissions. A true Tiptronic transmission is not a computer controlled manual transmission (with a conventional clutch), or semi-automatic transmission. Most Tiptronic implementations still make some shifts automatically, primarily to protect the engine and transmission. For example, as used by licensee Audi, the five-speed Tiptronic will automatically make the upshift from 1 to 2 when moving off from a stop, even when in manual mode; the transmission then waits for the user's upshift command before proceeding from 2 to 3, 3 to 4 and 4 to 5, although the transmission will still upshift if the redline is approached. On deceleration, the transmission will make all downshifts automatically when close to the tick-over or idle speed, to avoid running the engine at too-low an RPM, although the user can accelerate any downshift that would not exceed the redline.
Most luxury vehicles with a Tiptronic transmission have two fully-automatic modes: the primary mode, identified as "Drive", "Comfort" or similar; and another, usually called "Sport," which delays upshifts for a sportier driving at the expense of fuel, wear, comfort, and noise. Furthermore, because modern Tiptronic-type transmissions use an electronic control unit (ECU), sometimes specifically referred to as the transmission control unit, the transmissions are able to adapt to the user's driving style through "fuzzy logic". Shift points are tailored to the driver, improving shift quality.
[edit] Tiptronic S
The Tiptronic S is an upgrade to the original Tiptronic, with the ability to adapt to driver's behaviour, and also allows driver to change gears without entering manual mode.[1] In manual mode, if there is no manual input for a period of 8 seconds, the system reverts to automatic mode.[2] It was used as early as 2000 Porsche Boxster.[3]
In the Porsche Cayenne, the Tiptronic S was upgraded to 6-speed.[4]
In the Porsche 911 (997) Turbo, the Tiptronic S model has faster acceleration over manual counterpart.[5][6]
[edit] General automatic transmissions
Many automatic transmission computers send commands to the engine controller to reduce torque in low gears or at shifting and also to allow the engine to blip the throttle during downshifts for a smoother shift, reducing the "jerry" by the wheels, which affects traction.
