In engineering, the Miller cycle is a thermodynamic cycle used in a type of internal combustion engine. The Miller cycle was patented by Ralph Miller, an American engineer, dated Dec 24, 1957. The engine may be two- or four-stroke and may be run on diesel fuel, gases, or dual fuel. This type of engine was first used in ships and stationary power-generating plants, and is now used for some railway locomotives such as the GE PowerHaul. It was adapted by Mazda for their KJ-ZEM V6, used in the Millenia sedan, and in their Eunos 800 sedan (Australia) luxury cars. More recently, Subaru has combined a Miller-cycle flat-4 with a hybrid driveline for their concept "Turbo Parallel Hybrid" car, known as the Subaru B5-TPH, and Nissan has introduced a small three-cylinder engine with variable intake valve timing that claims to operate an Atkinson cycle at low load (thus the lower power density is not a handicap), or a Miller cycle when under light boost in the low-pressure, supercharged variant, returning to regular (and either suction or more strongly supercharged), more power-dense Otto cycle operation at higher loads. In the latter example, the particular nature of the Miller cycle permits the supercharged version to not only be moderately more powerful, but also claim better, almost diesel-like fuel economy with lower emissions than the (simpler, cheaper) suction-intake one - in contrast to the usual situation of supercharging causing significantly increased fuel consumption. Overview A traditional reciprocating internal combustion engine uses four strokes, of which two can be considered high-power: the compression stroke (high power flow from crankshaft to the charge) and power stroke (high power flow from the combustion gases to crankshaft). In the Miller cycle, the intake valve is left open longer than it would be in an Otto-cycle engine. In effect, the compression stroke is two discrete cycles: the initial portion when the intake valve is open and final portion when the intake valve is closed. This two-stage compression stroke creates the so-called "fifth" stroke that the Miller cycle introduces. As the piston initially moves upwards in what is traditionally the compression stroke, the charge is partially expelled back out through the still-open intake valve. Typically, this loss of charge air would result in a loss of power. However, in the Miller cycle, this is compensated for by the use of a supercharger. The supercharger typically will need to be of