Atkinson-cycle Questions

[GrahamC]

We're getting a Prius and have questions.

Can anyone suggest a technical article on the Atkinson-cycle engine used in the Prius. I know all the hoopla has been around the electric persona of the Prius, but two aspects of the gasoline engine are intriguing: its high compression ratio (13:1) and it low specific efficiency (50HP per litre). Also, is it really an Atkinson-cycle or a Miller-cycle? Heavy stuff, this.

I'm sure there are interesting reasons for these figures but they do go against conventional wisdom.

I'd be interested in comments from Toyota technical people about the Atkinson-cycle, too.

[02RSX90camry]

isn't a miller cycle a supercharged engine (as in the 3.2L miller-cycle used in the millenia S)?

[Tideland Prius]

http://en.wikipedia.org/wiki/Atkinson_Cycle