A couple observations...
Most folks (neo-luddites?) who are afraid of many of the more advanced technologies, usually use some GM product / technology failure as the example, and GM uses that to stick with old designs I'm sure. Think about it, direct injection, turbos, diesels, power windows, ABS (sensors), and on and on. Technology that GM released half baked, and now GM fan boys use this as their justification for ludditism. We are hearing the same baloney about the aluminum construction now as well.
Ford has stepped up and pushed technology ahead with their new engines, and their R&D for the last 10 years has been on the money.
GM's displacement on demand cylinder shutdown, closes the valves on the deactivated cylinders to reduce pumping losses, but does not eliminate frictional losses of having a full V8's friction drag all the time. That said, if you can tolerate the lack of response from the powertrain, you can get pretty good mileage out of them, especially the latest direct injected ones.
EPA ratings Ford's smaller DI/FI engines are attainable, but the readily available torque, and refinement encourages drivers to use the boost, and not the "eco". Driven gently, the mileage potential is quite amazing, and from time to time I drive my ecoboost work vehicle gently, and it gets great mileage, but the reality is, I accelerate and drive much faster in general because it's quiet, smooth, refined, torque rich vehicle.
