Worse City mpg? Than what, the gen II? Or theoretical gen III, had it used a smaller ICE. Not sure of your basis of reference. Bottom line, the OP's whining about the gen III "ONLY" averaging 50mpg. So, under the NEW epa standards, there are how many mid sized cars that were made with more cargo room than previously, and getting 50mpg (never mind the 'extra power' criteria)? Oh, none? Maybe I'm not understanding why is the OP upset. Maybe it's a "glass is half empty" thing. I suppose we all were hoping the gen III would be 100mpg, cost 1/2 as much and exhaust rose petals ... dangit. And I was hoping to win the lotto in my 30's too. What was it they told us at PCD ? Over 200 new patents?
I'm not exactly a pro with cars or anything....but the displacement...thats a mix of air and fuel right? What if the Prius just made better use of the fuel it already uses, and they put in a bigger engine that uses more air, to combust said fuel more efficiently? Is that realistic/possible?
That is a worldwide number, so one invention results in multiple patents. I heard >300 US patents. In any event, there's no dispute that the 2010 includes substantial new technology content.
I believe the idea is that a larger displacement engine produces more torque. Therefore at freeway speeds the larger displacement engine can run at lower RPM, hence that results in improved freeway mpg. The air/fuel ratio has to be maintained within relatively tight tolerances. If the ratio is too rich, then efficiency and mpg is reduced. If the ratio is too lean, more NOx is produced. Engine exhaust valves and the catalytic converter may be damaged due to higher combustion chamber temps.
I believe that with the new exhaust recovery system, people across various temperature ranges will begin to see more CONSISTENT mileage. Those in winter areas will probably see dramatic improvements due to the harvesting of otherwise wasted exhaust heat.