Mercedes-Benz 7G-Tronic Transmission

Mercedes-Benz 7G-Tronic Transmission

7G-Tronic is Mercedes-Benz's trademark name for its seven-speed automatic transmission. This fifth-generation transmission was introduced in the Autumn of 2003 on 8-cylinder models, and was the first seven-speed automatic transmission ever used on a production vehicle.

The 7G-Tronic debuted on five different eight-cylinder models: the E500, S430, S500, CL500, and SL500. It is also available on some six-cylinder models including the new 320 CDI engines which uses a VTG turbo charged common rail diesel engine.

However, all V12-powered cars such as the S600 and S65 AMG still retain the 5G-Tronic, which has a torque capacity of 796 lb·ft (1,079 N·m), as the newer 7G-Tronic is limited to 542 lb·ft (735 N·m), not enough to handle the torque from the V12 engine. Also, while rear-wheel drive W211 E-Class cars have adapted the 7G-Tronic, these with 4MATIC retain the five-speed automatic, although the next-generation W212 E-Class released for the 2010 model year adopted 7G-Tronic all across the lineup including 4MATIC.

The company claims that the 7G-Tronic can save up to 0.6 litres of fuel per 100 kilometers (depending on the car) and has shorter acceleration times and quicker intermediate sprints than the outgoing 5-speed automatic transmission.

The 7G-Tronic has two reverse gear ratios: 3.416 and 2.231. The winter mode, also recently named 'comfort' mode, starts out in 2nd forward and 2nd reverse.

The transmission can skip gears when downshifting, allowing for quicker acceleration. It also has a lockup torque converter on all seven gears, allowing better transmission of torque for improved acceleration. The transmission's case is made of magnesium, a first for the industry, to save weight.

The 7G-Tronic is the fifth-generation transmission for Mercedes-Benz. About 65 percent of Mercedes-Benz C-Class sedans, wagons, and sport coupes are purchased with automatic transmissions (with that figure rising). However, about 88 percent of Mercedes-Benz E-Class sedans and wagons are purchased with automatic transmissions, and automatic transmissions are standard on the Mercedes-Benz S-Class.

The 7G-Tronic transmission is built at the Mercedes-Benz Stuttgart-Untertuerkheim plant in Germany, the site of Daimler-Benz's original production facility.

The 7G-Tronic is currently available on the SsangYong Chairman W.

In July 2009, Mercedes-Benz announced they are working on a new nine-speed automatic.

Read more about Mercedes-Benz 7G-Tronic Transmission:  AMG SpeedShift MCT