Here is some more info on the W5A580 transmission:
The W5A580 debuted in 1995 Mercedes-Benz passenger vehicles and is known to be one of the smoothest, most fuel-efficient and cost-effective transmissions in the industry. Its unique three-channel torque converter helps provide an exceptionally smooth ride and shifting, while reducing fuel consumption. A $455 million upgrade project at the Indiana Transmission Plant was started in 2001 and completed in 2003. The 600,000 SF plant was designed to produce around 400,000 of the W5A580 transmissions per year for the North American market. The transmission project was the first joint effort between the company's American and German wings after the Chrysler Corp. and Daimler-Benz merge in 1998.
A broad ratio spread from First to the Fifth was selected to minimize fuel consumption and reduce powertrain noise during cruising. An aggressive First-gear ratio provides excellent launch performance, and evenly spaced gear ratios provide smooth acceleration through the gears.
World-class efficiency is achieved through physical and electronic means. This transmission uses bearings to reduce friction in many locations where other transmissions may utilize bushings. The transmission also uses a unique scavenging system that removes oil spun off of the rotating parts by centrifugal force through strategically placed slots in the outside of the case. This saves energy that would be consumed by internal parts rotating in oil. Lubricating holes in the clutches are also positioned to promote quick passage of the transmission fluid through the discs, minimizing viscous losses due to trapped oil.
The shift schedule adapts to individual driving style, driving situation and road conditions, altering shift points based on an accelerator pedal usage, brake usage, lateral acceleration, altitude and load on the car as a result of grades. Electronically controlled engine torque management provides quick wide-open-throttle up shifts and quick two-step (4-2 or 3-1) kick-down shifts that are exceptionally smooth.
Transmission ratios:
Gear W5A580
1st .........3.59
2nd ........2.19
3rd......... 1.41
4th...........1.00
5th .........0.83
Reverse ..3.16
Fully adaptive electronic control of all shifting makes shifts very smooth. The system monitors the transmission as shifts occur and adjusts hydraulic pressure as needed. In so doing, the controls make the powertrain feel responsive without harshness.
Driver recognition software alters shift points based on accelerator pedal usage, brake usage and lateral acceleration. This does not require a compromise between sporty and economical operation, nor is it a question of choosing one or the other.
A torque management system uses engine torque modeling to facilitate smooth transmission shifting. Because of electronic throttle control, torque management is more sophisticated and covers a broad torque range. Torque converter clutch slippage is electronically modulated and provides for partial engagement in Third, Fourth or Fifth gears. This results in improved shift feel, fuel economy, driveability and cooling. It can be used at lower speeds to provide benefits over a broad speed range. The system disengages as required to provide optimal performance.
