More data on Subaru's B5-TPH green concept
The Subaru TPH powertrain in the B5-TPH places a thin, 10-kW motor generator between a newly-developed 2.0-liter Miller cycle engine and the automatic transmission.
The engine is based on the standard Legacy 2.0-liter Boxer (horizontally opposed) engine, with modifications to the cams and engine management software to implement the Miller cycle.
A Miller-cycle engine (similar to the Atkinson cycle) leaves the intake valve open during part of the compression stroke. The late closing of the intake valve eliminates the substantial amount of energy normally required to overcome friction (as well as pumping losses) in the process of completing a normal compression stroke. The result is increased engine efficiency, at around 10%–15%, although with a loss of power.
