7G-Tronic (coded 722.9) 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 passenger 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.[2] 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.
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