5G-Tronic is Mercedes-Benz's trademark name for its five-speed automatic transmission, starting off with the W5A 580 and W5A 330 as core models.
Abstract
The 5G-Tronic is an electronically shifted 5-speed overdrive automatic transmission with torque converter lock-up and 2-speed for reverse. In all applications this transmission is identified as the New Automatic Gearbox Generation One, or NAG1. It replaced the older 4-speed 4G-Tronic transmission-family and its 5-speed derivative, and was replaced by the significantly more complex and cost-intensive 7-speed Mercedes Benz7G-Tronic transmission with 11 main components, introduced in 2003. Due to its high torque capacity and lower cost, it was still retained for turbocharged V12 engines, four-cylinder applications and commercial vehicles for almost a decade. It is still being built for niche applications.
Specifications
Basic concept
Technical and economic progress is reflected in 5 forward gears out of 9 main components, compared to 5 forward gears out of 11 main components in the direct predecessor.. It is fully electronic controlled and equipped with a torque converter lock-up.
Gear ratios
Special operating modes
Winter Mode
Activated by a toggle switch, Winter mode sets the gearbox to start off in 2nd gear, both in Drive and Reverse. This is designed to reduce wheelspin on icy surfaces. With Jaguar XJR applications the switch is labelled "Sport". In regular driving mode the gearbox starts off in 2nd gear, and will only engage 1st gear when triggered via the kickdown switch. While "Sport" mode is enabled the gearbox will always starts off in 1st gear.
Speedshift (2001-)
Speedshift is a performance feature set for the Mercedes-Benz transmissions which includes manual mode and active downshifting. When cornering at high speed, the transmission maintains the same gear above a certain lateral acceleration level. It can also automatically downshift before overtaking. It was first used in 2001 Mercedes-Benz C 32 AMG and 2001 Mercedes-Benz SLK 32 AMG.
AMG Speedshift (2002-)
A version with mechanical lock-up of the torque converter from first gear and steering-wheel-mounted shifter. AMG Speedshift is also used in 7G-Tronic transmission. It was first used in 2002 Mercedes-Benz E 55 AMG, S 55 AMG, C55, CL 55 AMG.
