Agreed. Most Europeans have become very American like in the level of comfort they will accept as a minimum now.
Long gone are the days of the 2CV and Beetle, now it has to have A/C, PS, comfortable interior etc all adding to the weight of the vehicle.
IMO this is the hinge that can tip the scale from a decent performing economy car to a gas swilling under powered pig.
Put that engine in something, small, totally stripped, without creature comforts and yes it will perform well enough and get the desired economy.
Again just MHO but i cant see many American drivers either buying or driving a car with these minimal specs.
An old bug or 2CV would go like stink with that power plant though.