20% fuel savings..... so if the car normally gets 40mpg on the highway, it will now get "upto" 48mpg.
Is that their example or one that you made up ? I seriously doubt that 2 cylinders would cut it at "normal" highway speeds. Around 30 in town, sure; at 50, maybe; at 70 or more, no way. Oh, and while this method of implemantation might be new, an engine with true VVT can also effectively shut down one or more cylinders if it's programmed to do that. For some reason it doesn't seem to have caught on much; don't know why.
How much power does it take to simply cruise at 70mph, 30hp? This engine can produce in excess of 100hp. It probably can enter 2 cylinder mode more readily than the Civic VX entered lean burn. The mean reason, I believe, that cylinder deactivation hasn't been used in a 4 cylinder, despite being used for years in 6 and 8 cylinders, has to do with NVH. If it ran too rough on 2 cylindcers, no one would want it.
The range extender on a the A1 E-tron concept had 250cc of displacement. A 6hp walk behind lawn mower is around half that. The rotary configuration Audi used also produces more power per displacement than a piston engine.
It depends on aero drag and the terrain but I doubt that 30 HP would be enough at 70 or above. And it seems lately like 70 is not an upper limit but a lower one.
The lower end of power output for this engine is 122hp(performance models get up to 180). On 2 cylinders, the output will be less than half that. But this was revealed in 2012, is already available in Europe. and should be in the US soon to answer our questions on it.
