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Toyota's own Jon F. Thompson, editor of the Open Road blog, has taken the time to explain one of the things that makes the engine of the Toyota Prius different than most other sedans. Sure, it's powered both by an electric motor and an internal combustion engine, but there is something a bit different about this particular four cylinder in that it runs the Atkinson cycle. Other hybrids, such as the Escape hybrid SUV, also run this cycle, which differs in a few important ways from the more traditional Otto cycle. Click here for the entire piece at the Toyota blog. For those who just want the basics, the Atkinson features a longer power stroke than the compression stroke by keeping the intake valve open longer than is normal. Although some of the fuel is pushed back through the intake, overall economy is increased. Toyota combines the Atkinson cycle with am electric motor assist, CVT transmission and variable valve technology. Isn't learning fun?

[Source: Toyota]