Multitronic

This article may need to be wikified to meet Wikipedia's quality standards. Please help by adding relevant internal links, or by improving the article's layout. (May 2008)

It has been suggested that this article or section be merged into Continuously variable transmission. (Discuss)

Multitronic^[1] is a stepless transmission launched by Audi in 2000. Based on the principles of continuously variable transmission (CVT) popularised by DAF, Multitronic offers a stepless automatic transmission in which the ratio between the input shaft and output shaft can be varied continuously within a given range, providing a very large number of possible ratios. The Multitronic system uses a chain drive, an oil cooled multiplate clutch (initially of six parts, later of seven to enable it to cope better with the torque of larger turbodiesel engines), and complex electronics, to overcome the traditional shortcomings of CVTs.

Multitronic (spelled by Audi with a lower-case leading 'm') is a registered trademark of Audi AG.

Function

The transmission is monitored and regulated by Audi's "Dynamic Regulating Programme" (DRP), which tracks the driver's inputs, driving conditions, and engine load to compute the optimal gear ratio for fuel efficiency or maximum performance, as mandated by the user. The transmission can select pre-programmed underdrive to increase performance, or overdrive to improve economy. From 2004, Multitronic gearboxes offered manual selection of a sport mode to pre-select the performance mapping. The electronic system also includes sensors to detect whether the vehicle is traveling downhill, and provides additional engine braking in such circumstances. Multitronic also offers a number of driver-selectable fixed ratios, selectable from either the gear-lever in a sequential style, or via (optional) fingertip paddle-shift controls. Early versions offered 6 ratios; in 2004, this was increased to 7, while new Audi models allready have multitronic transmission with 8 ratios. Some A6 variants that feature the Multitronic gearbox are now equipped with the fingertip controls as standard. These controls can also switch to semi-automatic mode when one of the paddles is activated; however, they revert to fully automatic after a predetermined period of time of inactivity.

Real world performance

Multitronic offers performance and economy similar to, and in some cases better than, the equivalent six-speed manual gearboxes, and greatly superior to the traditional automatic transmission.^{[citation needed]} Particular performance advantages are noticed in 'in-gear' acceleration times over equivalent manual transmission cars.^{[citation needed]}

Multitronic is offered on front wheel drive versions of the Audi A4, Audi A5, Audi A6 and the 2.0 TSI SEAT Exeo. It is not compatible with the quattro (four-wheel drive system), or transverse engine in the Audi A3. At first the torque limit was 310 N·m (230 ft·lbf), but the gearbox is now modified to withstand 400 N·m (300 ft·lbf) torque.^{[citation needed]}

References

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (March 2009)

External links

• Audi.com official Corporate website
• AudiWorld October 1999 article on the new Multitronic transmission