The Mercedes Benz’s trademark seven-speed automatic transmission is called the 7G-Tronic transmission. It is the 5th generation transmission system and it has been in production since 2003. It was introduced on 8 cylinder cars and was the first ever 7-speed automatic transmission used by passenger cars. It was initially introduced in five different 8 cylinder models: the E430, S500, CL500, E500 and the SL500. Mercedes claims that the 7G-Tronic transmission can save up to 0.6 liters of fuel per 100 kilometers.
Here is a video that tells us more about this innovative transmission system: