645Ci:
325 hp 4.4L V8
Only available in Manual 6 speed, Auto or SMG
M6:
500hp 5.0L V10
Available in Manual or SMG
Fully optioned
Better suspension
The 2007 BMW M6 has 40 valves.
The 2009 BMW M6 has 40 valves.
The 2006 BMW M6 has 40 valves.
The 2014 BMW M6 has a V8 engine.
The 2008 BMW M6 has a V10 engine.
The 2014 BMW M6 has 32 valves.
The 2013 BMW M6 has a V8 engine.
The 2006 BMW M6 has a V10 engine.
The 2009 BMW M6 has a V10 engine.
The 2007 BMW M6 has a V10 engine.
The 2008 BMW M6 has 40 valves.
The 2010 BMW M6 has a V10 engine.