GM-GMC: about displacement on demand technology, ac delco, eficiency

Question
i want to know the working of this displacement on demand engine its, advantages,disadvantages and the electronic system working used for controlling of inlet and outlet valve .  

Answer
Shaikh,

   I would also like to know more about this sytem but GM is keeping its information on this sytem pretty secret. I understand that it is much like the old Caddilac engines where certain cylinders are "shut-Down" when engine load is low, in effect lowering the fuel consumption. And reducing wear and increasing engine life. ***Claimed by GM*** Basicly I always thought it a silly idea, the pistons still move up and down in the bores and the valves still opened the spark plug symply did not fire. So.....reduced wear...I don't think so and further the "Dead" cylinders preduced drag when not fired reducing the eficiency of the remaining cyl. And...all of this was so problematic that GM abandoned the idea all together not long after. So, lets hope this new sistem works a little better. I have a heavy load of training coming up in the fall, with AC DELCO taught by a BCIT instructor that also works with GM engeniering, so I'll pick his brain about this "new" system, if you want try asking me again then and hopefully I'll be able to share more!