The Sequential Manual Gearbox, aka Sequential M Gearbox ( since, for now, the only US BMW to have SMG-II is the E46 M3 ). It's not an automatic, and its not a manual. It's a sort of mix between the two. There's no torque convertor ( like a manual ), yet the driver can opt to have the onboard computers change gears for him ( like an automatic ). Oh, and there's no need for a clutch -- SMG-II does it all itself via hydraulics.
OK. So picture a manual, but without a clutch pedal. Instead of the conventional
H-pattern, SMG-II gives drivers something different. Drivers can still
opt to row their own gears ( hitting the rev limiter just like a normal manual ),
but changing gears happens in the blink of an eye by pulling back or forward
on the "shifter". 80milliseconds. No human could possibly change that
fast. Oh, and if you have to downshift, you'll even get a little
throttle blip as SMG-II matches revs. Heel-toe driving gone, perfect
shifts every time.
BMW North America plans to offer SMG on at least the new 3-series, Z4, and, of course, the M3 models. The SMG used in the non-M flavors will be different than the M-flavored one.
For more info: