Interesting thermodynamics, given the energy source for an engine is the finite sum of chemical energy stored in the fuel.
On regular gasoline our 6.0 V8 @ 400hp generates ~4,180,000 BTU per hour. In other words 1642 hp total fuel energy is generated to produce 400 hp at the flywheel (25% thermal efficiency). The rest goes out the exhaust as lost heat, into the cooling system (coolant, oil and surrounding airflow).
So for a 1500cc engine to produce same 400hp at the flywheel would mean 100% thermal efficiency using same regular gasoline.
Else it uses different fuel or significantly more fuel, even with a turbocharger the BSFC vs stoic ratio doesn't add up.
No, it's not just because racecar or turbos rule, this goes beyond the thermodynamics of an Otto cycle, the engine likely uses combined heat and power (CHP).
From the pics this engine appears to have no cooling system apart from the rail on the underside of the intake and exhaust near the valves, I suspect thermal efficiency gains come from unseen technology components in the handbag sized turbo air pump.
I think it incorporates a heat engine design similar to the Stirling Engine.
http://en.m.wikipedia.org/wiki/Stirling_engine
