Filed under: MPG, BMW, LightweightThe next generation of BMW's 5-series sedan is expected to debut early in 2010, perhaps at the Geneva Motor Show. The new M5, however, likely won't be launched until the 2011 Frankfurt show. According to Albert Biermann, development boss of the M division, when it does arrive, it will cut CO2 emissions by 20 percent compared to the current model. To do that, BMW will follow an increasingly common path with direct injection, turbocharging and revised...