4 cylinder de-activation

[Jer4.8is]

This may sound like a silly question, but I've heard that the 4.8is engine has a de-activation feature of 4 cylinders when driving on the highway. Has anyone else heard this same information? The BMW brochures do not mention it. It seems unlikely to me.

[johnlacson]

AFAIK, BMW does not implement cylinder deactivation on any of its models. (I think they tried before on a 750i V12 but I'm not sure about this either) EfficientDynamics takes the car as a whole and applies little tweaks here and there to boost overall efficiency.

CD was more a Benz thing if I remember correctly, specifically on their V12 S600. Half the engine would shut down turning it into an i6 S300. But the fuel savings on CD engines was too small relative to the complexity and mechanical issues that plagued all brands that used it (Cadillac, MB, Honda) it became easier, cheaper, and more reliable to do other things (like BMWs double and triple stage turbos) than to do a CD.

[Jer4.8is]

Thanks for the info. It seemed unlikely to me as well.

[Clockwork]

John, the M70/M73 engines in the 7 & 8's have a feature called Limp Home Mode where half the engine would power down but the other half still worked to get you safely somewhere, but this never something an owner wanted to voluntarily introduce into the driving experience.

[Jer4.8is]

Thanks for the info. Love the girlfriend similarity.