Mazda’s Simple Engine Mod Burns 20% Less Gas

Mazda’s new Miller-cycle engine will power the new Mazda2, (named the Demio for the US).

Mazda Motor Corporation has developed a new, naturally
aspirated 1.3-liter Miller-cycle gasoline engine, which will power the all-new Mazda2
when it goes on sale in Japan
in July 2007. The Miller-cycle engine
usually depends on having a really big super charger but Mazda has figured out
a way to use the Miller-cycle on a normally aspirated engine.

The Miller-cycle is a fancy name for a simple change in the
valve timing for an engine.  It allows
the compression stroke of a 4-cycle engine to begin later than typical. Less power wasted on compression means more
efficiency. 

In combination with MazdaÂ’s first continuously variable
transmission (CVT), the engine enables the new Mazda2 to offer 54 mpg US, an
improvement of approximately 20% compared with MazdaÂ’s current 1.3-liter
engine model.

In addition to the new powertrain, the all-new Mazda2 has
been made approximately 220 lb lighter than its predecessor through a strict weight
reduction program, which results in quick handling to go along with the
significantly improved fuel economy.

I
can see no reason that the Miller-cycle engine can’t be used to improve
the efficiency of larger engines and/or engines in hybrids.  I wonder
what the carbon footprint of a Miller-cycle hybrid car running on
cellulosic ethanol would be?

Via Green Car Congress