And I adored my Fix or Repair Daily 65 Mustang (18mpg and problem free), as well as my very economical, inexpensive, well made Escorts of the 80s and 90s (45+mpg). I said that earlier, but here it is again like it or not.
The price difference between a Prius 1 and and Escort will pay many times over for the small incremental fuel economy that the Prius might obtain.
I don't have facts to back this up, but I would bet that the extra energy and the extra pollution resulting to create the Prius was many times the small fuel economy benefit. There is a huge increment in electronics and batteries that are notoriously dirty for creation and burial. So whether you are green oriented, or $$ oriented (also known as green), the result is the same. Now these kinds of hybrids are VERY good for URBAN drivers (bad for us country drivers), but you urban drivers should be using your mass transit system anyway, right????
But I also acknowledge, and say internally at my job very frequently, that Ford has no product other than the Escape Hybrid that attracts the green consumer, or no product at all that attracts the entry consumer or the economy minded consumer. I believe this is a very serious business mistake, and have said so many times now, and 8 years ago when our European derived CEO Jacque Nasser (and very much loved by the MBA community) made the edict that Ford's future would be in the solitary basket of large trucks and large SUVs and the PAG (Premium Automotive Group, Jaguar, Volvo, Landrover, Aston Martin). To me, this was a "going out of business commitment, which we now see that I was right. Many a good executive found his career terminated if he dared disagree with Nasser's principles, and with "Shareholder Value" which was just a way to rob the bank account.
I'm not familiar with what you are referring to by Rosen motors, but gas turbine engines are notoriously dirty with nitrogen oxides, a precursor to ozone and smog.