[nimbius]

cylinder deactivation has been a settled technology for about a decade now. northstar engines did it...to varying degrees of belt-eating self destruction...its likely a great option for long-haul drivers that spent a good deal of time at one speed.

as for auto start-stop, it smacks of desperation. every one of these systems more than doubles the load on the starter motor without giving any concrete numbers for expected fuel or carbon savings. its also worth remembering starting a car includes a fueling requirement itself.

[iggldiggl]

One edition of the owner's manual for the Mitsubishi Mirage (Space Star in certain parts of the world) has CO² emissions figures as measured under both the old NEDC and the new WLTC standards. For the smaller 1000 ccm engine model in combination with manual transmission, start-stop saves a measly 1 g/km as measured per NEDC, and actually uses 1 g/km more if measured according to the WLTC.