I have often said that this so-called TERS will give about 10-20% 'free' power (as the NACA showed nearly 70 years ago)
and so can reasonably be regarded as increasing maximum engine efficiency by that 10-20%
ie we can get 10-20% more power at that same rate of fuel consumption
however,typically this does not lend itself to reduced fuel consumption (eg of road cars)
at partial torque/power the 'free' torque/power will be cancelled by increased throttling to contain output to that partial torque
this is how we drive the public highway
true, this effect would be slighty offset if the gearing were raised by the 3-4% permitted by the 10-20% output gain
(this situation is a parallel to the somewhat futile raising of CR/fuel Octane for road cars)
greater offset is of course available if the car has a large but conveniently empty store for energy recovery
though this is anyway not particularly efficient (compared with direct use of exhaust-recovered electrical energy)
to get the proper economy benefit from TERS we need to further downsize the engine correspondingly about 10-20%
(this beyond the already envisaged level of downsizing-by-turbocharging)
ie we should design our (electrically) turbo-compounded engine to the same power as the uncompounded engine we are replacing
though old-school downsizing by customer (buying only twice the engine power needed not five times) works with any engine type
as does the the elimination of throttling inefficiency by other means ie radical redesign of engine or transmission
one aim of the 2014 activity is to facilitate hybridisation by stealth and covert European (and Japanese ?) protectionism
this involves buying complicated and expensive cars
the 3 European parents of these F1 engines are all supported to some extent by 'public-interest' oriented investment
once, in 1991, the French govt campaigned (unsuccessfully of course) for EU policy to encourage the small-engined, simple cars
at one time also the Japanese govt encouraged these