Actually, in the mid eighties, cadillac offered a v-8 with the ability to shut off cylinders to improve economy. they called it the five litre 4-6-8. I had one. And got to replace the computer 3 times in the six months I owned the car. It was a big failure. GM may be a little hesitant to offer such a feature again, even though the technology is a lot better now.

 

That blows. To the regular people that are not car people, when GM comes out with the DoD it will look like they copied the technology from DCX. Even though we have known for some time now that they were working on it, and would be putting it into production soon.

 

Probably not worthwhile on Diesels. DOD's benefit is at light engine loads where a normal gasoline engine is notoriously inefficient. Diesel engines are already amazingly efficient at light loads so there's virtually nothing to gain.

 

DOD improves effeciency by operating fewer cylinders at wider throttle settling - less pumping loses.

Diesels have no throttle blade - the amount of fuel injected determines power output. They have virtually no throttle-related pumping loss, so DOD wouldn't be as effective.

 

Looks like HONDA is also in the running to beat GM (when's GM due?)

From the car connection:

Also, beginning this fall, Variable Cylinder Management (VCM) will debut on some of Honda's V-6 engines, improving overall fuel economy by allowing models so equipped to operate on three cylinders in light load and cruising conditions.

 

well nobody will really be impressed by Honda having it prolly. It if anything is probly expected from its consumers. "My v6 Accord get 34mpg instead of 31 now!" they won't care.