Besides reading the owners manual regarding start/stop and understanding it's full capabilities, here is a comprehensive description:
http://www.bimmerfest.com/news/60650...-f30-3-series/
A few key features:
- It won't shutdown a cold engine
- There are several ways to temporarily defeat it, without shutting it off (for example applying extra brake pressure when stopped then easing off the brake slightly or turning the steering wheel).
- When stopped, coolant will still continue to circulate through the engine and turbos due to the electric water pump.
As all North Americans are "nubes" when it comes to understanding and using start/stop properly, it will take time and increased fuel prices to appreciate it the way many Europeans do.
Automatic start/stop is a key feature on mid-sized cars such as the VW Passat or BMW 320d that enables them to exceed 60mpg (50 US mpg / 4.7 l/100km) on the combined city/highway cycle.