Bimmerfest - BMW Forums - View Single Post - Whats SMG exactly?
View Single Post
Old 04-22-2007, 06:23 PM
gbelton's Avatar
gbelton gbelton is offline
///M for Motor Sports!
Location: NJ
Join Date: Aug 2003
Posts: 2,945
Mein Auto: No More 6 Series
Okay, One More Time...

Electrohydraulic manual transmission or clutchless manual gear system is a manual transmission system that works similar to a manual transmission but operates the clutch automatically. To change gears, the driver selects the desired gear, and the system automatically operates the clutch and throttle to match revs and engage the clutch again. Depending on the implementation, some transmissions will automatically shift gears at the right points and others require the driver to manually select the gear even when the engine is at the redline. Also, many such transmissions operate in sequential mode where the driver can only upshift or downshift by one gear at a time. Despite superficial similarity, clutchless manual transmission differ significantly in internal operation and driver's 'feel' from manumatics, which are automatic transmissions (using torque converter instead of clutch to manage the link between the transmission and the wheels) with ability to signal shifts manually.

Mercedes-Benz have named their system Sequentronic and BMW refer to their system SMG (Sequential Manual Gearbox; as used in the M3). The BMW SMG transmission has both automatic and manual shift modes. Inside the different modes there are different programs. The automatic programs range from A1 through A5, with the lower numbers representing slower and less agressive shifts. The manual shift mode ranges from S1 through S6, again with S1 for slower shifts and S6 for the quickest and most agressive shifts possible. Toyota also had a similar transmission on the MR2 Spyder, which is known as the Sequential Manual Transmission (SMT).
The Tail of The DRAGON, YES!!

2008 Alpine White, Portland Brown ///M5 (SMG)
2008 Alpine White, Fox Red ///M3 (6MT)
2008 Sapphire Black, Black 750Li
Reply With Quote